United Nations Secretary General Kofi Annan said Iraq was in the grip of civil war as United States and Iraqi forces attacked insurgent bases in a bid to shore up the authority of a government itself riven by factional rivalries. Outgoing Defence Secretary Donald Rumsfeld was revealed to have acknowledged in a memo just before he lost his job that US strategy was not working.

Gunmen in Iraqi police uniforms rounded up dozens of men at a government building in central Baghdad on Tuesday and drove off, in what may be the biggest mass kidnapping seen in a city becoming used to such violence. A spokesperson said dozens of men — ”100 or maybe 150” — had been rounded up.

Bombings and shootings killed up to 61 people in Iraq on Tuesday, including at least 26 soldiers, undermining the government’s attempts to show it can suppress unremitting violence. A roadside bomb attack on a bus filled with Iraqi troops on a road between Tikrit and Baiji, north of Baghdad, killed at least 23, the army said.

Bombs killed at least 40 people on Tuesday, half of them Iraqi soldiers, in the latest blow to the new government’s efforts to inspire confidence in the country’s security forces. The most dramatic blast was a roadside bomb attack on a bus filled with soldiers on a road between Tikrit and Baiji north of Baghdad. At least 20 of them were killed.

Gunmen wearing uniforms of Iraqi security forces kidnapped 25 people from an office in central Baghdad in broad daylight on Monday, police said. The gunmen pulled up in 15 four-wheel-drive vehicles and kidnapped employees and customers at the office on a street in Arasat, once a thriving commercial district.