Bombs explode at two Hamas security compounds in Gaza

Unidentified persons set off bombs at two Hamas security compounds in the Gaza Strip early Sunday, causing no casualties, the Palestinian Islamist group said.

There were no immediate claims of responsibility for the attacks on the Ansar-2 prison and the Gaza residence of Palestinian President Mahmoud Abbas, whose secular Fatah faction was forced out of the territory by Hamas in a 2007 civil war.

With Abbas now based in the West Bank, his Gaza residence is under Hamas control and some Fatah members say they were detained there. Hamas has not confirmed that the building is used as a stockade.

Security sources in Israel, which fought a December-January war with Hamas, denied involvement. Internal and sometimes violent challengers to Hamas rule include surviving Fatah cells and breakaway Islamists professing allegiance to Al-Qaida.

A Hamas security official said that the explosions, which took place within minutes of each other and which local residents described as sounding consistent with hand-laid bombs or grenades, had hurt no one.

"An investigation is under way," the official said.

Following the explosions, Hamas security forces erected checkpoints across Gaza City, stopped cars and prevented journalists from reaching the scene. Police declared western Gaza a closed military zone.

There was no immediate comment by Hamas officials of the Interior Ministry, however, dozens of Hamas security men were seen closing streets and stopping and searching cars.

No one has claimed responsibility for placing the bombs.

Two weeks ago, Hamas security forces killed 24 people, including the political and military leaders of a radical group called Ansar Jond Allah (Warriors of Gaza) in a mosque in the southern Gaza Strip town of Rafah.

The Al-Qaida inspired group has repeatedly threatened on its Web site to avenge the deaths of its leaders.