A number of rockets were launched from the Gaza Strip toward Israel on Monday, AFP journalists said, while Israel's army said an Israeli bus was hit by fire from the Palestinian enclave.
It was not clear if there were any injuries. Palestinian security sources also reported that a Hamas observation point was hit by tank fire in the Gaza Strip.
The flare-up follows a clash that erupted during an Israeli special forces operation in the Gaza Strip late Sunday that killed eight people. Hamas had vowed revenge.