By Nidal al-Mughrabi
GAZA (Reuters) - Israel launched an air strike in Gaza City on Thursday, the Islamist group Hamas said, after a day in which about a dozen mortar bombs and rockets fired from the coastal territory struck inside the Jewish state.
There were no immediate reports of casualties from the attack which caused explosions, and sent smoke and flames shooting into the air.
The Israeli armed forces had no immediate comment.
Hamas, an Islamic militant group that rules Gaza, said an Israeli warplane had bombed a building that witnesses said appeared to belong to the Islamic Jihad militant group.
Militants barred reporters from reaching the area.
The strike appeared to be Israel's first inside the crowded city of Gaza since a three-week offensive last January in which 1,400 Palestinians and 13 Israelis were killed.
Israel earlier distributed leaflets in Gaza, warning many of its 1.5 million residents to avoid areas within 300 metres (yards) of the border fence with Israel.
The mortars and rocket fired at Israel earlier on Thursday caused no casualties, an Israeli military spokesman said. The number of such attacks has been on the rise in the past few weeks after months of relative calm since the Gaza war.
(Writing by Allyn Fisher-Ilan)