A female suicide bomber killed at least 16 people on Tuesday northeast of Baghdad after she set off a belt of explosives in the midst of a gathering of Iraqi police recruits, police and a hospital official said.

The bomber made her way into a crowd of about 200 volunteers at a police station in the Iraqi city of Muqdadiyah, about 90 kilometres northeast of Baghdad, according to a police officer who spoke on condition of anonymity.

A car bomb on Tuesday killed at least six people at a checkpoint near Baghdad University. Another blast about 90 km away in Muqdadiyah killed at least 16.
(Khalid Mohammed/Associated Press)

The belt of explosives was hidden under an Islamic gown, Reuters news agency reported.

Dr. Abdul Salam al-Jibour at Muqdadiyah General Hospital confirmed that 16 people had died and 33 people were injured by the explosion.

Also on Tuesday, a U.S. soldier died in the Iraqi western province of Anbar during combat operations.

According to the Associated Press, at least 3,285 members of the U.S. military have died in the war since the U.S. first invaded Iraq in March 2003. The number includes seven military civilians.

Meanwhile, Iraqi Prime Minister Nouri al-Maliki said Tuesday that the Iraqi government believes there is no need for the U.S. to issue a timetable for withdrawing its forces from the country. Al-Maliki was visiting Japan on a four-day trip.

"We see no need for a withdrawal timetable. We are working as fast as we can," al-Maliki said.

"To demand the departure of the troops is a democratic right and a right we respect. What governs the departure at the end of the day is how confident we are in the handover process."

Al-Maliki said he thinks "achievements on the ground" should be the overriding concerns.

On Monday, tens of thousands of Iraqis protested in the streets of two Shia Muslim holy cities to demand that the U.S. withdraw its troops.

Muqtada al-Sadr, a powerful Shia Muslim cleric, called for the demonstrations to mark the fourth anniversary of Baghdad's fall. The demonstrations were peaceful.

U.S. forces swept into Baghdad on April 9, 2003, 20 days after the U.S.-led invasion.

According to BBC News, suicide bombings carried out by women are not common in Iraq but they have occurred. In February, for example, a major bombing at a Baghdad university was the work of a female suicide bomber.

With files from the Associated Press