BAGHDAD, Iraq - Insurgents exploded two car bombs in a Baghdad market and two more in Saddam Hussein's hometown of Tikrit on Sunday, killing a total of 21 Iraqis and wounding 73 in one of the bloodiest days since Iraq's historic elections.
The anti-coalition forces have grown more emboldened in the past week, bringing down a civilian helicopter carrying 11 people Thursday and striking with bomb attacks across Iraq Saturday, killing at least 16 people, including an American soldier. The violence — largely targeting Iraqi police and security forces — has played out as the National Assembly struggles to assemble a government.
Earlier Sunday, the U.S. military said it arrested four more suspects in Thursday's downing of a civilian helicopter north of Baghdad, bringing the number apprehended so far to 10. All 11 helicopter passengers and crew were killed, including one shot by insurgents.
The Baghdad bombs killed 15 people and wounded 40. The first exploded in front of an ice cream shop in the western al-Shoulah district, police Maj. Mousa Abdul Karim said. As people rushed to assist the wounded, a second bomb detonated within a few minutes, he said.
The U.S. military said it received a report that at least one explosives-rigged car, parked near an Iraqi police station in western Baghdad, had detonated, causing some 30 casualties. It had no further details.
Earlier, a car bomb exploded outside a police academy in Saddam Hussein's hometown, and another one went off moments later as authorities rushed to the scene, killing at least six Iraqis and wounding 33, officials said.
The carefully coordinated attack by insurgents in Tikrit occurred as academy recruits were about to travel to Jordan for training, said police Lt. Shalan Allawi.
As police imposed a curfew in the city, Mohammed Ayash, a doctor at Tikrit General Hospital, said four policemen and two civilians were killed by the bombs, and 33 people were wounded, most of them policemen. Tikrit is 80 miles north of Baghdad.
South of the capital, three insurgents were killed Sunday as the roadside bomb they were trying to plant in the town of Mahawil exploded, said police in nearby Hillah.
In the Baghdad area, insurgents attacked several U.S. military convoys Sunday. In one attack, a roadside bomb hit a convoy in the east, killing one American soldier and wounding two, the U.S. military said. Iraqi police said two Iraqi civilians also were wounded in the attack.
Also, the military announced another casualty from a day earlier — an American sailor who died Saturday when the Marine convoy he was traveling with was hit by a roadside bomb in Fallujah, 40 miles west of Baghdad. Sailors sometimes participate in such operations in support roles such as medics.
At least 1,567 members of the U.S. military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.
The military said a bomb also exploded near a U.S. patrol in western Baghdad on Sunday, but no one was hurt.
Ahmad Chalabi, head of an Iraqi exile group that provided intelligence to the United States on Saddam's weapons programs, told CNN on Sunday that part of the problem was the continuing stalemate among Iraqi politicians on naming a government.
Iraqi leaders are struggling to form a Cabinet that will include members of the Sunni minority, believed to be the driving force in the insurgency.
"We need a government immediately. The delay in forming a government has encouraged the terrorists," Chalabi said, referring to the Sunni-dominated insurgency.
The American military said Sunday it detained four additional suspects in the downing of the helicopter during the previous 24 hours. Iraqi civilians helped U.S. forces locate the first six suspects captured Saturday, the military said.
The Russian-made Mi-8 helicopter was shot down about 12 miles north of Baghdad. The dead included six American bodyguards for U.S. diplomats, three Bulgarian crew members and two security guards from Fiji, officials said.
Two militant groups claimed responsibility for the attack and released video to back their claims. In one video, insurgents are seen capturing and shooting to death the lone survivor, identified as a Bulgarian pilot.
The aircraft was owned by Heli Air of Bulgaria and chartered by Toronto-based SkyLink Aviation Inc.
The six Americans were employed by Blackwater Security Consulting — a subsidiary of security contractor Blackwater USA of Moyock, N.C., which had four employees slain and mutilated by insurgents in Fallujah a year ago.
Iraqi police and Task Force Baghdad soldiers also apprehended 16 other terror suspects around the capital, Sunday's statement said. Eleven of them were captured during a U.S. raid on a village north of Baghdad early Sunday.
The suspects are believed to belong to a terrorist cell that carried out bombing and mortar attacks.
New information also appeared to emerge about four hostages being held by insurgents.
Two women identified as relatives of an Iraqi American who was kidnapped along with three Romanian journalists in Baghdad last month were shown on Al-Arabiya television Sunday, begging for his release.
With tears in their eyes, the women described as Mohammed Monaf's sister and mother said he had returned to Iraq to visit his sick father after living in exile for 25 years.
"I'm Mohammed's sister. I appeal to the kidnappers to release my brother because he is an Iraqi citizen and has come to Iraq to visit my father," the younger woman said, wearing a green veil over her head and holding documents she said showed her brother's Iraqi citizenship.
The older woman, wearing a white veil, spoke next, saying: "My son was kidnapped on his first time to visit Iraq since he left in 1980. I urge the kidnappers to give my son back."
Neither woman gave her name during the brief video.
On Friday, Al-Jazeera television aired part of another video in which it said a militant group was threatening to kill the three kidnapped Romanian journalists — Marie Jeanne Ion, Sorin Dumitru Miscoci and Ovidiu Ohanesian — and Monaf, described as their translator, unless Romanian troops leave the country within four days.
Romania, a staunch U.S. ally, has about 800 troops serving in Iraq.
The four hostages were kidnapped March 28 near their Baghdad hotel shortly after interviewing interim Prime Minister Ayad Allawi. They appeared a day later in another video aired on Al-Jazeera.
On Saturday, Associated Press Television News cameraman Saleh Ibrahim, a father of five in his early 30s, was killed when gunfire broke out after an explosion in the northern city of Mosul. AP photographer Mohammed Ibrahim was wounded in the same incident.
The circumstances of the death and injury remained unclear.
The explosion happened around 2:30 p.m. (6:30 a.m. EDT) near al-Yarmook circle in the city 225 miles north of Baghdad, according to other journalists who responded to the blast. The cause of the explosion was not immediately determined.
U.S. forces took Mohammed Ibrahim away after hospital treatment Saturday but released him about midday Sunday. A U.S. military official, who would not allow the use of his name, said the two men had been "caught up in the sweep after the situation."
