A loud explosion rocked Gaza City (search) early Monday, and residents said they believed it was an Israeli air strike.

Palestinian ambulances raced to a site in the northern part of the city, in the Sheik Radwan (search) neighborhood, residents said. There were no immediate reports of damage or casualties. Residents said Israeli attack helicopters were flying over the area before the explosion.

The blast came a few hours after two Palestinian suicide bombers blew themselves up at the Israeli port of Ashdod, killing 11 Israelis.