A tenuous cease-fire between Israel and Palestinian militants in the Gaza Strip was punctured Wednesday by a deadly Israeli airstrike that triggered rocket and mortar fire at Israel.

After 48 hours in which air attacks were suspended, an Israeli drone strike killed Ismail Asmar, a senior member of the armed wing of the Islamic Jihad group, in his car in Rafah, near the border with Egypt, according to the military and local medical officials.

An Israeli army statement said Asmar was involved in arms smuggling and efforts by Gaza militants to attack Israel from Egypt’s Sinai Peninsula. In a cross-border attack from Sinai last week, eight Israelis were killed north of the resort town of Eilat, setting off a string of airstrikes in Gaza and rocket attacks on southern Israel that lasted five days.

The hostilities tapered off after a cease-fire was mediated by Egypt.

But after Wednesday’s airstrike, Gaza militants fired mortar rounds and four rockets into Israel, lightly wounding an infant, the Army said. One of the rockets, fired at the city of Beersheba, was intercepted by the Army’s Iron Dome missile defense system, the military reported.

Islamic Jihad asserted responsibility for the mortars and rockets, calling them retaliation for the killing of Asmar.

The Israeli military said it targeted from the air two militants who had fired the mortars and two rocket squads. The armed wing of Islamic Jihad later said that one of its members was killed.

In expectation of further attacks from Gaza, residents in southern Israel were ordered in radio announcements to remain close to bomb shelters.

Egypt’s state news agency reported that a woman was injured by a rocket fired from the Gaza Strip into the Egyptian part of Rafah, which straddles the Egypt-Gaza border. The incident was the first in which a rocket had hit a residential area in Rafah, raising concerns among local security forces, an official told Reuters news service.