Heavy machinegun fire rocked the Sabah Bahrat square in central Damascus on Tuesday, witnesses said.
“Machinegun fire was heard in the Sabah Bahrat square, and members of the security forces, armed with Kalashnikovs, ran across the square,” site of the country’s Central Bank, witnesses told AFP.
Shooting was also reported in Baghdad Street, a main road near the square.
As many as 17 people have been killed by Syrian forces across the country on Tuesday, Al Arabiya reported citing activists at the Syrian Revolution Commission.
The Local Coordination Committees, earlier, denied the presence of any massacres inside a Falouja School at the Palestinian Yarmouk refugee camp, following reports by activists that the Syrian regime troops had stormed the camp, Al Arabiya reported on Tuesday.
Syria’s military deployed armored vehicles near central Damascus on Monday as troops battled rebels around the capital in what activists said could be a turning point in the 16-month uprising.
Rebels late Monday announced the launch of a full-scale attack operation.
The Free Syrian Army’s central-Homs Joint Command said its operation was launched “in response to massacres and barbaric crimes” committed by the Assad regime.
The FSA, the statement said, started to conduct “attacks on all security stations and branches in the cities and the countryside, to enter into fierce clashes (with their forces) and to call on them to surrender.”
The FSA called for all international roads to be cut off, “from (northern) Aleppo to (southern) Deraa and from (eastern) Deir Ezzor to (coastal) Lattakia, to cut off and seize the supply lines.”
Battles rages around Damascus
As battles raged around Damascus for a second straight day, troops deployed armored vehicles near the historic neighborhood of al-Midan.
“When there is fighting in the capital for several hours, even days, and troops are unable to control the situation, that proves the regime's weakness,” Rami Abdel Rahman of the Syrian Observatory for Human Rights told AFP.
Online videos showed street battles in the capital, with fighters firing off rocket-propelled grenades from behind sandbags.
An activist on the ground, identifying himself as Abu Musab, said the army was trying to overrun al-Midan and called the fighting a “turning point” in the revolt against Assad's autocratic regime.
Damascus -- and Syria’s largest city, Aleppo -- are both home to elites who have benefited from close ties to Assad’s regime, as well as merchant classes and minority groups who worry their status will suffer if Assad falls.
But for months, rebels have been gaining strength in poorer towns and cities in the Damascus countryside. Some activists suggested Monday that recent government crackdowns in those areas had pushed rebels into the city, where they were determined to strike at the heart of the regime.
“It seems there is a new strategy to bring the fighting into the center of the capital,” activist Mustafa Osso told The Associated Press. “The capital used to be safe. This will trouble the regime.”
The fiercest fighting was in the southwest neighborhoods of Mazzah, Kafr Souseh, Midan, Tadamon, Nahr Aisha and al-Zahira, while activists also reported clashes in the western suburbs and in the northern neighborhood of Barzeh.
Amateur videos posted online Monday gave glimpses of the fighting. In one, a dozen fighters crouched Sunday behind sandbags, firing at a tank down a rubble-strewn street with a machine gun and rocket-propelled grenades.
Another video showed a burnt station wagon with at least three charred bodies inside that an off-camera narrator said were government troops.
Yet another video showed dozens of protesters who had blocked traffic on the main highway entering the city from the south with burning tires, bricks and pieces of metal fencing. Hundreds of cars were backed up in both directions.
A video apparently shot later in the day showed army vehicles and troops blocking the entrances to an adjacent neighborhood.
The authorities vowed on Monday they would not surrender the capital. “You will never get Damascus,” read the headline in al-Watan newspaper, which is close to the regime.
Activists said residents were fleeing Tadamon, with many seeking shelter in the nearby Yarmuk Palestinian refugee camp, as the opposition Syrian National Council accused the regime of transforming Damascus into “battlefields.”
Rebel-held districts of the central city of Homs, which has been under siege for months, were also bombarded on Monday, according to the Observatory.
It said a total of at least 67 people were killed on Monday in violence across the country -- 32 civilians, 21 soldiers and 14 rebel fighters.
Syria in a state of civil war
In Geneva, the International Committee of the Red Cross said Syria is in a state of all-out civil war and that all sides must respect humanitarian law or risk war crimes prosecutions.
“Each time there is fighting we can see conditions that can be defined as a non-international armed conflict,” ICRC spokesman Alexis Heeb told AFP, adding “international humanitarian law applies” in such circumstances.
Nawaf Fares, the first Syrian ambassador to defect, warned Assad will use chemical weapons against opposition forces and may have already deployed them.
Fares, the most prominent politician to defect since the uprising against Assad began, insisted the president’s days were numbered but warned he would be prepared “to eradicate the entire Syrian people” to remain in power.
When asked by the BBC’s Frank Gardner whether that would mean the use of chemical weapons, Fares said: “I am convinced that if Bashar al-Assad’s regime is further cornered by the people, he would use such weapons.”
The latest violence comes as diplomatic pressure builds ahead of a key Security Council vote to decide if the 300-strong U.N. Supervision Mission in Syria (UNSMIS) will be renewed on Friday.
The unarmed observers are tasked with overseeing implementation of a six-point peace plan brokered by U.N.-Arab League envoy Kofi Annan which has been flouted daily since mid-April when it was to have gone into effect.
Security Council talks on Syria virtually collapsed Monday, leaving the major powers heading for a veto showdown on a proposal to impose sanctions on Assad.
Russia will veto a western resolution linking the renewal of the U.N. mission with sanctions when it comes to a vote on Wednesday, its U.N. ambassador Vitaly Churkin said after council talks.
A rival Russian resolution just proposing to renew the U.N. mission would fail to get enough votes from the 15 council members to pass, U.S. envoy Susan Rice told reporters. Russia is Assad's main ally.
Russia slammed as “blackmail” Western pressure to push for a U.N. Security Council resolution against Syria’s regime, as a top defector warned that President Bashar al-Assad would not hesitate to use chemical weapons against his own people.
Annan is in Moscow for talks with Foreign Minister Sergei Lavrov and President Vladimir Putin while UN chief Ban Ki-moon is due in Beijing on Tuesday, also on a mission to get support for tougher action on Syria.
Russia and China have twice blocked resolutions against Syria at the Security Council which is divided over Western calls to pile new sanctions on Damascus.
The diplomatic moves come after Syria denied its troops carried out a massacre in the central village of Tremsa, where activists said dozens of people were slaughtered on Thursday by troops and pro-regime militiamen.
More than 17,000 people have been killed since the uprising began, according to the Observatory.
The Syrian regime has grown increasingly isolated throughout the crisis, with a number of Arab and Western nations withdrawing their ambassadors to protest the crackdown.
On Monday, Morocco asked the Syrian ambassador to leave the country. Within hours, Syria's state-run TV said the Foreign Ministry had declared Morocco's ambassador to Syria persona non grata.