BAGHDAD—Iraqi security forces have arrested members of an al-Qaida-linked insurgent cell responsible for deadly attacks and robberies in Baghdad, a police official said Sunday.

Lt. Col. Nimir Sultan Halan, the head of a police intelligence unit, said that the dismantled 25-person cell belongs to Ansar al-Islam, a radical Sunni Arab group linked to al-Qaida. He did not say when the actual arrest took place.

Ansar al-Islam had previously threatened to attack the Arab League summit in Baghdad and any political or business officials associated with it. The summit, held last month, was almost violence-free.

Halan said the cell was behind robberies on money exchange companies in the capital that were used to financially support the group.

"The families of the victims have filed lawsuits against the arrested members who will stand trial," he added.

Iraqi authorities seized several bombs and pistols fitted with silencers as part of the operation, he said.

Meanwhile, a rare explosion in the northern city of Irbil wounded one person Sunday. The attack was caused by a bomb stuck to a car, said the city's police chief, Brig. Gen. Abdul-Khaleq Talaat.

Irbil is in Iraq's largely peaceful Kurdish region, 217 miles (350 kilometers) north of Baghdad. The region has generally been free of the bombings and shootings that have plagued the rest of Iraq.

Violence has ebbed in Iraq, but Sunni insurgents still launch occasional attacks to challenge the Shiite-led government.

© Copyright 2012 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.