Israel reopened at least three of its border crossings with the Hamas-ruled Gaza Strip on Sunday after a halt to Palestinian cross-border attacks that had strained an Egyptian-brokered truce, officials said.

An Israeli military spokesman said Sufa commercial crossing, the Nahal Oz fuel transfer deport and the Erez border terminal for travellers resumed operations at 8 a.m. (6 a.m British time), with some restrictions still in force.

Peter Lerner, a liaison official with Israel's Defence Ministry, said earlier that another commercial crossing, Karni, would also be reopened, but this could not immediately be confirmed.

Israel closed the crossings on Wednesday after an Islamic Jihad rocket attack which the Palestinian faction called retaliation for the killing of one of its West Bank leaders.

The truce, which came into effect on June 19, calls for Hamas to stop cross-border rocket fire and for Israel to gradually ease its embargo on Gaza. It does not apply to the West Bank.

Hamas called last week for smaller Palestinian factions to abide by the ceasefire and said it would take "necessary measures" against violators.

Israel on Friday allowed fuel to reach Gaza's sole power station through Nahal Oz.

U.N. sources said that since the truce started, Israeli forces fired into the Gaza Strip at least eight times, wounding two people. Palestinians fired rockets and mortar bombs into Israel at least three times, according to the Israeli army.

Israel sharply cut back on the supply of goods into the Gaza Strip a year ago, after Islamist Hamas took over the coastal enclave from forces loyal to Palestinian President Mahmoud Abbas's more secular, Western-backed Fatah faction.