Shelling was reported in the Syrian towns of Homs and Rastan early on Tuesday, after as many as 43 people were killed on Monday, Al Arabiya reported citing Syrian activists.
A monitoring group said it was the most intense attack on the central flashpoint city of Homs and its Baba Amro area for days.
“The shelling of the Baba Amro neighborhood began at dawn and is the most intense in five days,” said Rami Abdel Rahman of the Syrian Observatory for Human Rights, citing activists on the ground.
“Two rockets are falling a minute on average,” the head of the Britain-based group told AFP on the phone.
Hadi Abdullah, an activist in Homs reached by telephone, said the shelling of Baba Amro was extremely heavy.
“The situation is tragic. There are pregnant women, people with heart problems, diabetics and, foremost, wounded people who we cannot evacuate,” he told AFP on the phone from Homs.
Meanwhile, Syrian Local Coordination Committees (LCC) said massacres were committed in the protest hub of Rastan on Monday against unarmed civilians. Reports of action on the ground are difficult to verify because Syria restricts access by journalists.
In Baba Amro, a rebel bastion in Homs, Syrian troops targeted vehicles carrying citizens who were trying to escape the violent crackdown, leaving scores of people dead, including children and women, LCC activists told Al Arabiya.
The Syrian Observatory for Human Rights said Baba Amro was hit by artillery.
“The neighborhood of Baba Amro has been subjected to sporadic shelling since 5:00 am (0300 GMT) by the Syrian army,” the Britain-based group said in a statement.
Al Arabiya showed footage of the destruction caused by the bombing of the Syrian cities.
Security forces also raided homes to arrest people in the southern Deraa province, cradle of the Arab Spring-inspired uprising against Assad’s iron-fisted rule.
“There were fierce clashes between defectors and the army which stormed Lajat (also in Deraa province) and arrested the mothers of four dissidents,” the Observatory said.
An Arab League peacekeeping plan for Syria was ignored on Monday and the U.N. rights chief said crimes against humanity had probably been committed in the country that has been rocked by protests for 11 months.
Syrian President Bashar al-Assad swiftly rejected the Arab League initiative for a joint mission with the United Nations to end the bloodshed, according to AFP.
The latest violence came as Navi Pillay, the U.N. High Commissioner for Human Rights, delivered a stark verdict on the consequences of the international community’s failure to pass a U.N. resolution condemning the deadly crackdown.
“The nature and scale of abuses committed by Syrian forces indicate that crimes against humanity are likely to have been committed since March 2011,” she told the U.N. General Assembly.
“The failure of the Security Council to agree on firm collective action appears to have emboldened the Syrian government to launch an all-out assault in an effort to crush dissent with overwhelming force.”
Activist Mohammad al-Homsi said the situation was getting worse. “Army roadblocks are increasing around opposition districts, there is a pattern to the bombardment now. It is heavy in the morning, then gives way to an afternoon lull and resumes at night,” Homsi told Reuters from the Homs.
“Shells are falling at random, almost everyone in a residential building in Baba Amro has moved to the ground floor. It is normal to find up to six families living together on the lower levels,” activist Hussein Nader said by phone from Homs.
The United States said it was considering whether a peacekeeping force would work while Russia, who with China vetoed a second U.N. resolution on Syria on Feb. 4, said a ceasefire was needed before peacekeepers can be deployed.
Despite the relentless violence, protests took place across Syria, where activists say more than 6,000 people have died in the crackdown since last March.
Some denounced Assad and others supported the rebel Free Syrian Army, according to YouTube videos provided by the LCC.
“Arab League!!! Thank you but we need more,” said a placard students carried at a rally in Jabala, in Idlib province.
A government official said Syria was determined to crush dissent, regardless of the latest Arab initiative, the official SANA news agency reported.
“This decision will not prevent the Syrian government from fulfilling its responsibilities in protecting its citizens and restoring security and stability,” the unidentified official was quoted as saying.
“Syria rejects decisions that are a flagrant interference in the country’s internal affairs and a violation of its national sovereignty.”
Activists say Assad’s forces have killed at least 500 people in Homs since they began bombarding it on Feb. 4 -- the day Russia and China vetoed the second U.N. Security Council resolution.
That move prompted the pan-Arab bloc after marathon talks in Cairo at the weekend to ask for a joint Arab-U.N. peacekeeping mission, but the Syrian regime rejected the suggestion on Sunday.
The Arab League plan was on Monday welcomed by Britain, Germany, Italy and the European Union.
U.S. President Barack Obama and British Prime Minister David Cameron renewed their condemnation of Syria’s crackdown during a discussion on Monday, the White House said.
U.S. Secretary of State Hillary Clinton meanwhile hit out at Syria’s latest military offensive.
“It is deplorable that the regime has escalated violence in cities across the country, including using artillery and tank fire against innocent civilians,” Clinton said in Washington at a joint press conference with Turkish Foreign Minister Ahmet Davutoglu, according to AFP.
Clinton said she welcomed a fresh chance to put international pressure on Damascus when the 'Friends of Syria’ group holds its first meeting in Tunisia next week and insisted more economic pressure would be exerted.
“We will strengthen our targeted sanctions, bring the international community in condemnation of the actions of the Assad regime,” the chief U.S. diplomat said.
Likely to fall
Analysts, however, said the new Arab initiative was likely to fail.
“I find it very difficult that we will find member states who will actually contribute U.N. troops to something like this,” said Salman Shaikh, head of the Brookings Doha Centre.
Davutoglu, who also met with U.S. Defense Secretary Leon Panetta on Monday, echoed Clinton’s remarks.
“There should be a new humanitarian initiative to reach out to people who are suffering because of the shortage of food, medicine everywhere in Syria,” he said.
He said he spoke with U.N. Secretary General Ban Ki-moon on Sunday about a Turkish initiative with the United Nations aimed at obtaining “humanitarian access” to Syrians in need.
The Turkish top diplomat welcomed the upcoming Tunis talks.
“The meeting in Tunisia will be an important international platform to show solidarity to (the) Syrian people and to send a strong and clear message to (the) Syrian regime that they cannot continue this,” he said.
The United States and Europe are reluctant to get dragged in militarily. Given Syria’s position on the region's religious, ethnic and political faultiness, they fear this would be more risky and complicated than the NATO-led air support that helped Libyan rebels oust Muammar Qaddafi last year.
British Prime Minister David Cameron and U.S. President Barack Obama agreed in a phone call on Monday on the need for “international unity ... including further action at the UN and a broad and strong coalition in the new Friends of Syria group,” Cameron’s spokesman said, according to Reuters.
The two leaders also “discussed the possibility of increasing the pressure on the Assad regime through additional sanctions,” the spokesman added.
Russia, Assad’s close ally and main arms supplier, said it could not support a peacekeeping mission unless both sides stopped the violence first.
China backed what it termed the Arab League’s “mediation” but offered no clear sign of support for the call for a joint peacekeeping force.
“Relevant moves by the United Nations should be conducive towards lessening tension in Syria ... rather than complicating things,” Chinese Foreign Ministry spokesman Liu Weimin said.