GAZA CITY — Four Palestinians from one extended family were killed and more than 40 others were wounded on Thursday after military ordnance exploded in Gaza as residents cleared the rubble of their homes a year after the war with Israel.

The toll made it the deadliest explosion to rock Gaza since the 50-day conflict last summer between Israel and Palestinian militants, officials from local human rights organizations said. It was not immediately clear whether the ordnance was left by Israeli or Palestinian forces.

Also Thursday, a driver plowed his car into a group of Israeli soldiers at a bus stop near a Jewish settlement in the occupied West Bank. Three were wounded, two seriously, and they were airlifted to a Jerusalem hospital, Israeli Army radio reported. Soldiers quickly shot the driver, believed to be a Palestinian from the West Bank village of Bidu. He was also in serious condition, the radio reported.

No Palestinian groups claimed responsibility for the attack, although the militant group Hamas praised it. It may have been another so-called lone-wolf attack, in which individual Palestinians, without any leadership or planning, attack Israeli soldiers and civilians with cars, knives or guns.