Baghdad ? A suicide bomber blew himself up Sunday in the midst of a celebration to welcome home an Iraqi detainee released from U.S. custody, killing at least 25 people, Iraqi officials said.

The U.S. military, meanwhile, announced the arrest of an al-Qaida in Iraq figure who allegedly planned the 2006 kidnapping of American journalist Jill Carroll – one of the highest-profile attacks against Westerners in Iraq.

The suicide attack occurred inside one of several tents set up outside a house in the Abu Ghraib area on Baghdad’s western outskirts, according to residents and police. It was unclear if the former detainee was among the casualties.

Residents and police said Ayyid Salim al-Zubaie, a local sheik in the mainly Sunni area, had invited dozens of guests to a banquet in honor of his son, who was released earlier in the day from Camp Bucca in southern Iraq.