Palestinian militants in the Gaza Strip fired a barrage of rockets into Israel on Wednesday, further dimming prospects of a new truce.

Militants fired about 60 rockets and mortar shells into southern Israel. No casualties were reported. The Israeli military said it later launched an air raid to target Hamas gunmen launching explosives into Israel. Palestinian medics said at least one gunman was killed.

Hamas' armed wing issued a statement saying Wednesday's rocket fire was in retaliation for the killing of three militants the day before by Israeli troops. The militant group also threatened more attacks in response to what it called Israeli aggression in Gaza.

Israeli Defense Minister Ehud Barak said those responsible for the rocket attacks would, in his words, "pay a big price."

The violence has hurt chances of renewing a cease-fire between Israel and Hamas that ended last week.

An Israeli spokesman, Mark Regev, blamed the militant group for destroying the six-month truce.

Palestinian President Mahmoud Abbas called for a renewal of the cease-fire on Wednesday.

And United Nations Secretary-General Ban Ki-moon issued a statement urged all parties to work to secure the immediate restoration of calm and the urgent easing of humanitarian conditions in Gaza.

The latest Palestinian attacks prompted Israel to cancel plans to allow deliveries of supplies into the Hamas-ruled Gaza Strip Before the violence escalated, Israel had agreed to ease its blockade on Wednesday to allow some aid into Gaza. An Israeli defense official, Peter Lerner, said the border would remain closed until further notice.

Israel has said its foreign minister, Tzipi Livni, will meet with Egyptian President Hosni Mubarak in Cairo Thursday for talks about a new truce in Gaza.

Some information for this report was provided by AFP, AP and Reuters.