Two more U.S. soldiers have been killed in separate overnight attacks in Baghdad, and at least four more wounded in another incident west of the city. The military says American troops killed at least two of the Iraqi attackers, and wounded several more.

Two of the overnight attacks took place in northwest Baghdad. In the first attack, the military says, two gunmen tried to ambush a U.S. convoy late Sunday in the Azamiyah neighborhood. The American troops returned fire, killing one of the attackers and wounding the other. One American soldier was killed in the battle, and the military says the wounded suspect has been taken into custody.

A few hours later, just across the Tigris River in the Kadhamiya neighborhood, another soldier was killed, when a homemade bomb hit his vehicle on a routine patrol.

Both soldiers were part of the First Armored Division, which is in charge of patrolling Baghdad.

The military says a third attack came in the form of a rocket-propelled grenade fired at a U.S. convoy in the flashpoint city of Ramadi, about 100 kilometers west of Baghdad. The attack wounded four U.S. soldiers. The Americans returned fire. Witnesses and the military say the troops killed at least one Iraqi attacker and wounded another.

The Ramadi attack came just days after an explosion killed seven Iraqi police recruits, as they graduated from a U.S.-sponsored training program in the city. It is part of the so-called Sunni Triangle, which is seen as a stronghold of continued support for ousted Iraqi leader Saddam Hussein.

Attacks on U.S. troops in Iraq have been a daily occurrence for weeks. But the attacks have grown bolder in the last few days, since the Al-Jazeera television network broadcast a taped message by a man claiming to be Saddam Hussein. He indicated he is orchestrating the attacks, and urged Iraqis to join in the resistance campaign.

Elsewhere, reports say American troops in northern Iraq have agreed to release 11 captured Turkish special forces soldiers, who were arrested several days ago. Turkish news media said the men were accused of plotting an attack on the Kurdish governor of Kirkuk.

The Turkish government strongly protested the arrests, and the incident has further strained the already-tense relations between the United States and Turkey. The two countries -- once strong allies -- fell out over the recent war in Iraq, and the Turkish parliament refused to allow U.S. troops to use Turkey as a base for the invasion of Iraq.

The United States is also concerned about the continued presence of Turkish troops in Iraq. The Turks say they are pursuing Turkish Kurdish separatists, but Washington fears their controversial deployment could further destabilize the Iraqi Kurdish region.