BAGHDAD - A woman with explosives hidden beneath her black abaya detonated them Tuesday in a crowd of about 200 police recruits northeast of Baghdad, killing at least 16 people, police and hospital officials said.
The woman walked into the crowd at the main gate of the Muqdadiyah police station and blew herself up, according to a police officer at the scene who spoke on condition of anonymity because he was not authorized to speak to the media.
At least 16 people were killed and 33 wounded in the mostly Sunni Muslim city about 60 miles northeast of Baghdad, said Dr. Abdul Salam al-Jibour at Muqdadiyah General Hospital.
Meanwhile, U.S. and Iraqi army forces were engaged in fierce fighting with gunmen in two Sunni-dominated neighborhoods of the capital, Fadhil and Sheik Omar, police and witnesses said.
An American helicopter in the battle came under ground fire but was not shot down, a senior U.S. military official said, speaking on condition of anonymity because U.S. officials were still investigating.
Police said six people, including an Iraqi soldier, were killed and 21 wounded. Repeated artillery fire rang out across Baghdad at midday, but the target was unclear.
A parked car bomb exploded at a checkpoint near Baghdad University, killing at least six people and wounding 11, police said. The bomb was packed into a yellow taxi cab near campus, and all of those hurt were civilians, police said.
A Katyusha rocket hit a basketball court at a boys school in eastern Baghdad, killing a 6-year-old boy and wounding 17 others -- 15 students and two teachers, police said.
The U.S. military announced the deaths Monday of four U.S. soldiers -- three killed by a roadside bomb and a secondary explosion in southeastern Baghdad and another killed in combat in western Anbar province.
The unit with the three dead soldiers had been conducting raids against militants in the area, and had recently captured five suspects, it said.
The fourth soldier was killed during combat operations in Iraq's western Anbar province, another statement said.
At least 3,285 members of the U.S. military have died since the beginning of the war in 2003, according to an Associated Press count. The figure includes seven military civilians.
Prime Minister Nouri al-Maliki, on a four-day trip to Japan, said there was no need to set a timetable for the withdrawal of U.S. troops from his country.
"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."
What counts, he added, are "achievements on the ground."
His comments came a day after tens of thousands of Iraqis took to the streets of two Shiite holy cities, demanding that U.S. forces leave the country. The massive rally, called for by rebel cleric Muqtada al-Sadr, marked the fourth anniversary of the fall of Baghdad.
Al-Sadr, who remains in seclusion and did not attend, ordered up the march as a show of strength not only to Washington but to Iraq's establishment Shiite ayatollahs as well.
He issued a statement Sunday urging his Mahdi Army militia to redouble efforts to expel U.S. forces and for the police and army to join the struggle against "your archenemy."
While he was in Japan, al-Maliki's office issued a statement saying he would travel to Egypt on April 20 for talks with Egyptian President Hosni Mubarak and the head of the Arab League, Amr Moussa.
It would be al-Maliki's first visit to Egypt -- the Arab world's most populous nation.
Also Tuesday, the U.S. military said it captured more than 150 suspected insurgents in a nearly two-week operation north of Baghdad. Rocket-propelled grenades and launchers, automatic machine guns, sniper rifles and anti-tank mines were also seized, it said.
