In the capital, about 600 Iraqi army soldiers and 250 US soldiers took part in Operation Muthana Strike, which began early on Monday and targeted alleged safe houses of armed fighters in neighbourhoods near the west side of Baghdad airport, the military said in a statement.
At least 100 men, including alleged foreign fighters, were arrested, the military said. Those captured included Egyptian suspects, it said.
Meanwhile, in western Baghdad on Monday, a car bomb detonated by remote control killed two civilians, including one woman and wounded four people, police said.
Elsewhere, four gunmen killed a senior member of the Kurdish Democratic Party's Mosul branch, a party spokesman said. Jirjis Muhammad Amin was shot inside his sister's home in the northern city.
A second attack by gunmen in Mosul, 360km northwest of Baghdad, killed a bodyguard of the provincial Nineveh governor, police said. He was killed in front of his home in the eastern part of the city, which is the capital of Nineveh province.
The joint US-Iraqi raid, which the military said was based on tip-offs from local residents, was designed to detain suspects, seize illegal weapons and gain intelligence to disrupt future attacks.
"The success of the Iraqi army demonstrates their level of training and high commitment to rid Iraq of terrorists," said US Colonel Kenneth Roberts in the statement.
Up to 600 Iraqi soldiers backed
the US troops in the raid
The operation concluded at about 9.30am (0530 GMT).
Elsewhere, gunmen in Baghdad killed an Iraqi painting contractor who worked with a US military base, doctors said. Umar Uthman and a friend were driving on Baghdad's dangerous airport road on Monday morning when the assailants opened fire. Uthman's friend was wounded.
Separately, the Iraqi army found the beheaded corpse of an unidentified man with his hands tied behind his back on Monday in Bani Zaid village, north of Baghdad, police said.
On Sunday, officials and witnesses said Ihab al-Sherif, 51, chief of Egypt's diplomatic mission in Baghdad, was seized on Saturday night by about eight gunmen after he stopped to buy a newspaper in western Baghdad.
Al-Sherif, who had been in the country since 1 June, was pistol-whipped and forced into the trunk of a car as the assailants shouted that he was an "American spy," witnesses said, speaking on condition of anonymity on Sunday because they feared reprisals.
"We know nothing at all. We don't know what the kidnappers want..."
Ihab al-Sherif, Egyptian envoy to Iraq's brother-in-law
Al-Sherif's brother-in-law and family spokesman, Yahia Hussein, said on Monday he has received no demands from the kidnappers nor the Egyptian Foreign Ministry, which has been in contact with Iraqi authorities. There has been no claim of responsibility.
"We know nothing at all. We don't know what the kidnappers want, but I am sure the Foreign Ministry is exerting all the effort to let him free," Hussein said. In Cairo, the Egyptian Foreign Ministry confirmed the diplomat was missing and said contacts were under way with the Iraqi government "and all other sides" to win his release.