Gunmen in police uniforms and driving vehicles used by security forces kidnapped five Britons from an Iraqi Finance Ministry office Tuesday and a senior Iraqi official said the radical Shiite Mahdi Army militia was suspected. The US military announced that 10 American soldiers were killed in roadside bombings and a helicopter crash on Memorial Day, making May - at 112 fatalities - the worst month for US forces this year. Baghdad police said two car bombers hit neighborhoods on opposite sides of the Tigris River on Tuesday, killing at least 40 people and wounding 123 others. A Shiite mosque was destroyed in the second of the two attacks in the Amil neighborhood in west Baghdad. And officials in restive Diyala province said they found 35 bodies dumped or buried in a newly dug mass grave. A morgue official in Baqouba, the provincial capital, and a spokesman at the provincial police operations center both reported the same figure, but refused to be named fearing reprisal from al-Qaida militants and Shiite militias battling for control of the region. Across Iraq, police and morgue officials contacted by The Associated Press reported a total of at least 120 people killed or found dead on Tuesday. All of the officials refused to allow use of their names fearing the could be targeted by militants. In the Baghdad kidnappings, about 40 heavily armed men snatched the five Britons from an Iraqi Finance Ministry annex and sped away in a convoy of 19 four-wheel-drive vehicles toward Sadr City, the Shiite Mahdi Army stronghold not far away, according to the British Foreign office in London and Iraqi officials in the Interior and Finance ministries. Joe Gavaghan, a spokesman for Montreal-based security firm GardaWorld, confirmed that four of its security workers and one client were kidnapped. All four GardaWorld workers are British citizens, he said, declining to provide more details. A spokesman for BearingPoint, a McLean, Virginia-based management consulting firm, said that one of the company's employees, apparently the client referred to by Gavaghan, was among those abducted. "We have been informed that a BearingPoint employee working in Iraq was taken from a work site early this morning," Steve Lunceford, the BearingPoint spokesman, wrote in an e-mail to AP. BearingPoint has been working in Iraq since 2003 on a US Agency for International Development-funded contract to support economic recovery and reform, Lunceford said. A senior official in the Iraqi Interior Ministry confirmed the five were British and that Mahdi Army militiamen were believed responsible. The official would provide the information only on condition that his name not be used. Maj. Gen. Abdul-Karim Khalaf, the Interior Ministry spokesman, said the abduction was carried out by men wearing police uniforms who showed up at the Finance Ministry data collection facility in 19 four-wheel drive vehicles of the type used by police. He said the band of kidnappers spedoff toward Sadr City, the Shiite Mahdi Army stronghold in northeastern Baghdad. Eight of the soldiers killed on Monday were from Task Force Lightning. Six of them were killed when explosions hit near their vehicles, two others in a helicopter crash. The military did not say if the helicopter was shot down or had mechanical problems. All eight died in Diyala province north of the capital. "We know that the helicopter had received ground fire, but do not know yet the cause of the helicopter going down," Lt. Col. Christopher Garver, a military spokesman, said in an interview with Associated Press Radio. Later Tuesday, the military said two Multi-National Divisi Tayaran Square, riddling cars with shrapnel, knocking over pushcarts and sending smoke into the sky, witnesses said. The blast killed 23 people and injured 68 others, a police official in the district said on condition he not be named. The official said his superiors refused to allow him to speak to reporters. Yousef Qasim, 37, was working in his fabric shop 200 meters away when the blast tore through a line of buses waiting at the square, he said. "I rushed there to see about four or five burning bodies," he said. "I saw flesh on the ground and pools of blood." Shop owners grabbed their wares and tried to flee, fearing a second blast, said Talib Dhirgham, who owns a nearby laundromat. Police who arrived at the scene confiscated the cameras of journalists who came to cover the aftermath, according to AP photographers and television cameramen who went to the scene. More than an hour later, a pickup truck parked next to a Shiite mosque in the Amil district in western Baghdad exploded, completely demolishing the mosque, killing 17 people and wounding 55 others, according to a second police official, who also spoke on condition anonymity because he felt use of his name would put his life in danger. The mosque was reduced to rubble and piles of brick, according to AP Television News video tape. Cars were flipped over, charred and dented. Residents pushed debris off nearby roofs. In a separate statement issued at Camp Victory, the US military said the Amil explosion was the work of a suicide bomber in a white Honda. The military did not give a death toll. "We will work closely with our Iraqi Security Force partners to bring those responsible to justice in accordance with Iraqi laws," said Col. Ricky D. Gibbs, commander of the 4th Infantry Brigade Combat Team, 1st Infantry Division. In other violence, gunmen in Samarra, 95 kilometers north of Baghdad, set up fake checkpoints on the outskirts of the city and abducted more than 40 people, most of them soldiers, police officers and members of two tribes that had banded together against local insurgents, a police official in the city said on condition of anonymity because he feared retribution.