BAGHDAD — For more than two months, British journalist Richard Butler had sat with a hood over his head wondering what his kidnappers in Basra were planning.

Suddenly yesterday, gunshots rang through the house where he was held. There were shouts. The door to his room burst open, and Mr. Butler tore off his hood to see Iraqi army soldiers.

They were as surprised to see Mr. Butler as he was to see them, according to Iraqi military officials, who described yesterday’s rescue of the freelancer, on contract with CBS News, as a lucky find during a search of a house for illegal weapons.

The defense ministry spokesman, Major General Mohammed al-Askari, said Iraqi forces stumbled upon Mr. Butler at about noon while conducting the search as part of a government offensive on illegal militias in Basra. He said “the elements” responsible for abducting Mr. Butler and his Iraqi translator February 10 had been captured but gave no additional details.

Mr. Butler’s translator was freed February 13 unharmed, but Mr. Butler had not been heard from since his abduction. It was not immediately clear who the kidnappers were and whether he had been held for ransom or strictly for political purposes.

His release came as the American military indicated that the offensive in Basra, which began March 25, had entered a new phase in which the heaviest fighting was over. A military statement said forces were focusing on clearing areas no longer under militia control and scouring them for weapons caches.

“Our forces now control most of Basra,” spokesman for Iraq’s Interior Ministry, Brigadier General Abdul Kareem Khalaf, said. He added that raids and arrests would continue.

Since the offensive, at least 15 police or soldiers in Basra have been killed and 400 wounded, a ministry official said yesterday. The official, who was not authorized to release the figures and asked to remain anonymous, said 400 alleged militants had been killed and hundreds wounded.