The raids aimed at capturing insurgents who have threatened to disrupt the election scheduled for Jan. 30, while Iraqi forces closed off the main routes into Baghdad following a wave of car bombings and shootings.
Troops from the Army's Stryker Brigade Combat Team detained nine people and seized weapons in the overnight sweeps in Mosul, the Associated Press reported. In the past two weeks alone, U.S. and Iraqi forces have rounded up 200 suspected insurgents in the northern city, according to the U.S. military.
The surge in car bombings and street fighting in Mosul follows the U.S. offensive in the former insurgent hub of Fallujah last November. U.S. commanders believe many insurgents who fled Fallujah have now set up new operations in Mosul and other nearby cities, the AP reported.
In the latest fighting Thursday, rebel fighters shelled the Al Salam Hospital in Mosul, where U.S. and Iraqi forces had taken up positions, hospital Director Faris Hani told the AP. Doctors and patients fled, but no casualties were reported.
Also in northern Iraq, a Brazilian working for a South American construction company was reported missing following a highway ambush near the city of Bayji on Wednesday. A British contract security worker and Iraqi guard were killed in the attack, Iraqi police Lt. Shaalan Allawi said Thursday.
Despite the efforts to crack down on the militants, an insurgent group, Army of Ansar al-Sunna, which has vowed to thwart the Jan. 30 elections, said it had killed a Briton and Swede, but did not mention the missing Brazilian worker. The group's statement, which appeared on an Islamic Web site, was not verified by the British Embassy, which said it did not have any details.
Meanwhile, the Chinese government on Thursday said it was negotiating for the release of eight Chinese hostages in Iraq who appeared in a videotape released Tuesday. Their captors threatened to kill them unless China clarified its position on the war in Iraq within 48 hours.
To date, militants in Iraq have kidnapped more than 180 foreigners as part of a campaign to force U.S.-led coalition troops and other westerners to leave Iraq and disrupt this month's elections.
In Baghdad, Iraqi forces began to seal off major highways leading into the capital from the west and south Thursday morning. The action comes a day after a series of deadly car bombings and shootings that killed at least 16 people.
Alaa Mahmoud, an Iraqi National Guard captain monitoring one roadblock, said he was under orders to prevent all vehicle traffic from entering the city, the AP reported.
Violence also flared in the southern part of the country where in the southern city of Basra, an explosion at the entrance to a logistics base wounded several British soldiers and Iraqi civilians Thursday afternoon. No deaths were reported.
A group led by Jordanian militant and al-Qaida ally Abu Musab al-Zarqawi claimed responsibility for the explosion, or what it called a suicide attack in revenge for the alleged abuse by British soldiers of Iraqi prisoners. That claim has not been verified.
Earlier Thursday, a separate audiotape purportedly from al-Zarqawi's group urged militants to prepare for a lengthy war against U.S.-led forces in Iraq, saying victory could take months or even years to free Iraq from American occupation.
In the near 75-minute tape posted on an Islamic Web site Thursday, the speaker, claiming to be al-Zarqawi, said militants were crushing the morale of the "tyrant" America.
"The fruits of jihad (holy war) come after much patience and a lengthy stay in the battlefield ... which could last months and years," he said. "In the fight against the arrogant American tyrant who carries the flag of the cross, we find that despite its military might it is being crushed emotionally and morally."
The speaker also said the assault on Fallujah had exposed the "apostate" Iraqi government and "ugly face of the rejectionists (Shiites)" and their leader Ayatollah Ali al-Sistani, according to the Agence France-Presse. The authenticity of the tape has not been verified.