The Palestinian militant group Hamas has announced an immediate ceasefire with Israel in Gaza.
A statement read by a Hamas spokesman said the group would hold fire for a week to give Israel time to withdraw its forces from the Gaza Strip.
The move came hours after a unilateral Israeli ceasefire came into effect.
The cessation of hostilities was earlier cast into doubt by fresh rocket fire into Israel and an Israeli air strike on militants in Gaza.
Hamas' deputy chief in Syria, Moussa Abou Marzouk, said the ceasefire was in the name of all "Palestinian resistance factions".
"We... announce a ceasefire of our factions in the Gaza Strip and we stress that our demand is the withdrawal of the enemy forces from the Gaza Strip within a week, along with the opening of all the crossings for the entry of humanitarian aid, food and other necessities for our people in the Gaza Strip."
Israelis and Palestinians give their views on Israel's ceasefire announcement
The group said the ceasefire would be temporary unless Israel met these long-standing demands.
The BBC's Bethany Bell, on the Israeli side of the border with Gaza, says Israeli helicopters and drones have been flying overhead and Israeli troops are on high alert.
Many people are hoping that a ceasefire will last, but no-one on either side of the border will be surprised if the fighting starts up again, our correspondent adds.
Hamas's leader in exile, Khaled Meshaal, will make an "important" announcement in Syria on Sunday afternoon regarding Israel's ceasefire, the Associated Press news agency reported.
Israel, whose ceasefire came into effect at 0200 (2400 GMT) has said its troops will stay in Gaza for as long as necessary.
Hours later, at least 18 rockets were fired into Israel, Israeli sources said, triggering an Israeli air strike in response.
One rocket hit a house in Ashdod, injuring lightly two people, police said.
The stopping of rocket fire had been a chief aim of the military campaign.
Israeli troops killed a Palestinian near the southern Gazan town of Khan Younis on Sunday morning, reports from Gaza said. If confirmed, the death would be the first fatality since the ceasefire began.
At least 1,300 Palestinians, according to Palestinian sources, and 13 Israelis have been killed since Israel launched its offensive on 27 December.
Palestinian medics say at least 50 bodies have been pulled from the rubble since Israel halted its offensive.