The Gaza-based militant group Islamic Jihad has weapons that can reach Tel Aviv, a member of the group's armed wing the Quds Brigades has told AFP in an interview.

The Quds Brigades fired most of the rockets that hit Israel in the past week's four-day conflict between Gaza militants and the Jewish state.

A member of the armed wing, who goes by the nom de guerre Abu Ibrahim, said the group was ready to expand the reach of its rocket fire beyond the Israeli town of Ashdod, which lies some 35 kilometres (20 miles) outside Gaza.

"If the occupation targets any leader of any Palestinian group whatsoever or any citizen, the Brigades will respond with force and expand the reach of the response beyond Ashdod," he told AFP.

"The enemy is aware of the range that the Brigades rockets can reach," he said, adding that the Quds Brigades possessed "many thousands" of rockets.

Islamic Jihad took the lead in attacking Israel during the recent confrontation, which began on March 9 with Israel's assassination of the commander of the Popular Resistance Committees militant group.

By the time a truce was announced on Tuesday, 25 Palestinians had been killed -- many of them from Islamic Jihad -- and at least 250 rockets had been fired into Israel, around 180 of them launched by the group.

Some rockets landed nearly 40 kilometres inside Israel, not far from the outskirts of Tel Aviv.

A lone rocket was fired from Gaza into Israel during the first 12 hours of Friday, the Israeli military said, as the fledgling truce firmed up.

Abu Ibrahim said the Quds Brigades have "developed long-range rockets and if the aggression returns, they could be used to reach towns far beyond Ashdod."

Abu Ibrahim said the group was receiving significant help from Lebanon's Hezbollah organisation, which he said provides "fundamental support" to the Quds Brigades, particularly by "facilitating the training of fighters."

Another Quds Brigades member, who spoke to AFP on condition of anonymity, said "certain resistance groups, including the Quds Brigades, have Fajr-3 and Fajr-5 missiles, with a range of 60-110 kilometres."

"But they are not for use unless Israel targets an important figure," he said.

He also claimed that Gaza militants possessed SAM-7 missiles which he said had been fired at Israeli helicopters last year.