Palestinian medical workers say at least two Hamas militants were killed in an Israeli air strike in the Gaza Strip Saturday, as the Jewish state intensifies efforts to end Palestinian rocket attacks into Israel.

The Israeli army says the air strikes were aimed at rocket launchers in northern Gaza.

Witnesses say Palestinian gunmen also exchanged fire with Israeli troops backed by tanks and bulldozers as they searched homes in the town of Jabaliya in the Hamas-controlled territory.

An Israeli offensive this week in Gaza has killed more than 30 Palestinians, mostly militants. Israeli officials say militants have fired more than 110 rockets into southern Israel in recent days.

In other news, Hamas said it has arrested a suspect in a plot by the rival Fatah movement intended to assassinate Hamas leader Ismail Haniyeh.

Former Hamas Interior Minister Said Siyam said Saturday a man planned to blow himself up as Haniyeh prayed in a mosque, and that the man confessed. Fatah denied involvement in the plot.

Hamas seized control of the Gaza Strip in June from Fatah, which is led by Palestinian President Mahmoud Abbas.

On Friday, U.N. Secretary-General Ban Ki-moon appealed for an end to the violence in Gaza and southern Israel. He called for the immediate end of Palestinian rocket and sniper attacks into Israel, and urged the Israeli military to use maximum restraint.

U.N. officials also asked Israel to reverse its decision to close its border with Gaza, saying the closure could worsen an already dire situation for Gaza Palestinians.

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