Hamas fired rockets at southern Israel on Saturday, hitting a house and a Jewish seminary just hours after five Hamas policemen were killed in Israeli air strikes.

No one was hurt in the strikes.

Hamas militants said they fired 15 homemade rockets at Israel. The Israeli military said five of them landed, one directly hitting a house in the border town of Sderot, a frequent target for militants. Another landed next to a Jewish seminary and another in the courtyard of a local college.

Nobody was hurt in the barrage, which came after Israel fired missiles at two Hamas police stations late Friday, killing five militants.

The newest round of cross-border attacks began earlier Friday when Hamas militants fired mortar shells that killed a 48-year-old Israeli man in a communal farm on the border with Gaza. Three others were wounded.

Palestinian militants frequently fire crude rockets and mortars into southern Israel from Gaza, killing 14 people in all since late 2001. The attacks often provoke Israeli airstrikes and ground incursions that kill far more Palestinians. Hostilities have ebbed since more than 120 Palestinians were killed in a flare-up of violence two months ago.

The recent attacks make Egypt’s fragile efforts to broker a truce on the Gaza-Israel border even more difficult. A spokesman for Hamas’ armed wing said his group would “continue fire until the last moment” before a cease-fire is completed.

Though both sides appear eager to halt the fighting, Hamas also wants Israel to end its blockade of Gaza, which is meant to pressure the group to stop Palestinian militants from firing their salvos into Israel.

The blockade has also caused widespread shortages of fuel and basic goods in Gaza. Hamas wants Israel and Egypt to reopen its borders with Gaza, sealed after the militant Islamic group seized control of the territory nearly a year ago.

Israel wants Hamas to release an Israeli soldier captured by Palestinian militants nearly two years ago.

The military said Friday that Palestinian militants have fired 1,950 mortars and rockets at Israel since the beginning of the year _ almost equal to the amount fired in all of 2007.