BAGHDAD, Iraq - Insurgents launched two major attacks today against a Shiite mosque and a police station in Baghdad, killing 30 people, including at least 16 police officers, the deadliest insurgent attacks in weeks.

In the north, U.S. and Iraqi troops battled insurgents in Mosul, leaving at least 11 guerrillas and a policeman dead, Iraqi commanders said. The fighting in Iraq's third-largest city - a center of violence since a major uprising last month - came a day after a U.S. soldier was killed in the city.

Jordanian terrorist Abu Musab al-Zarqawi's Sunni rebel group, al-Qaida in Iraq, claimed responsibility for the attack on the police station in Baghdad's western Amil district. The claim, which appeared on an Islamic Web site, could not immediately be verified.

"The destructive effect that such operations has on the morale of the enemy inside and on its countries and people abroad is clear," the claim said.

In the attack, gunmen first shelled the police station near the dangerous road to Baghdad International Airport. Then guerrillas stormed the station, killing 16 policemen, looting weapons, releasing detainees and torching several cars, Police Capt. Mohammed al-Jumeili said. He said several policemen and detainees at the station were wounded.

U.S. military spokesman Lt. Col. Jim Hutton said gunmen in 11 cars attacked the station with rocket-propelled grenades and small arms fire. He said a U.S. military Humvee was also damaged. There were no American casualties. There was no word on the insurgents' casualties.

The U.S. Embassy on Thursday barred employees from the highway leading to Baghdad's airport, the scene of frequent attacks on vehicles.

The attack on the Shiite mosque came in the Baghdad neighborhood of Azamiyah, a Sunni Muslim stronghold. Police said a car bomb exploded at the Hameed al-Najar Mosque, killing 14 people and wounding 19.

Azamiyah was a major center of Sunni support for Saddam Hussein, and the targeting of the mosque may have been a bid by Sunnis to stoke civil strife in the area. It wasn't clear who was behind the bombing.

Meanwhile, two city councilmen from Khalis were ambushed and killed by gunmen today, officials said.

The two were driving from Khalis, 50 miles north of Baghdad, to Baqouba, the capital of Diala province, to attend the regional meeting on the country's Jan. 30 elections, said deputy governor Ghassan al-Khadran. He said a third councilman was injured in the attack.

The claim from al-Zarqawi's group said 30 people were killed in the Amil attack and only two escaped. The group also claimed responsibility for an attack on a police station in Azamiyah. There were no reports of casualties from the strike on that police station.

In the same claim, Zarqawi's group said it attacked two police patrols in the western Baghdad area of Nafq al-Shorta, killing everyone, but that could not be verified.

The attacks were the latest against Iraq's police and security services, which have been targeted throughout central, western and northern Iraq in recent weeks.

In Mosul, fighting began when insurgents fired several mortar rounds at a U.S. base in Mosul, causing no damage or casualties. Iraqi and American forces went out to find the source of those attacks and came under fire from small arms and rocket-propelled grenades. Some of the gunmen took cover in a mosque that Iraqi commanders then cleared, finding stores of weapons, U.S. military spokesman Lt. Col. Paul Hastings said.

Maj. Gen. Rashid Feleih, commander of the Iraqi commandos force in Mosul, said gunmen also attacked two police stations, killing one policeman and injuring two. Police returned fire, killing at least 11 attackers and capturing three.

Mosul's police force disintegrated during an insurgent uprising last month, forcing the U.S. command to divert troops from their offensive in the militant stronghold of Fallujah.