BAGHDAD -- Insurgents killed four US soldiers in separate attacks yesterday as violence increased five days before national elections.
US officials announced the release of 238 detainees, but said the move was unrelated to any strife or to demands made by kidnappers of four Christian peace activists.
Two of the soldiers were killed by small-arms fire southwest of the capital, the US command said. The others died in a roadside bombing in Baghdad's Sunni neighborhood of Azamiyah and by small-arms fire north of the city, according to the command.
The US military also said an American soldier was killed and 11 others were wounded Friday in a suicide car bombing in the Abu Ghraib district of western Baghdad. That brought to at least 2,140 the number of US military members who have been killed since the war began in March 2003, according to an Associated Press count.
Concern mounted over the fate of the four activists as a deadline set by kidnappers threatening to kill them passed yesterday.
The Interior Ministry said it had no information about the hostages, and various emissaries sent from Canada and Britain showed no sign that they had established contact with the kidnappers.
A group calling itself the Swords of Righteousness Brigade seized the activists two weeks ago. It first set a deadline for Thursday, but extended it until yesterday without giving a precise hour.
The hostages are Norman Kember, 74, of London; Tom Fox, 54, of Clear Brook, Va.; and two Canadians, James Loney, 41, and Harmeet Singh Sooden, 32.
Sunni Arab clerics used their main weekly religious service on Friday to plead for the hostages' lives because of their humanitarian work and condemnation of the US-led war in Iraq.
US and British officials have expressed concern for the lives of the captives but made clear that they would not bow to the kidnappers' demands.
Yesterday, US officials said they had released 238 security detainees held by the multinational forces. But such releases are common, and are generally arranged weeks in advance. A US Embassy spokeswoman, Liz Colton, said the release was not in response to the kidnappers' demands.
Elsewhere, the body of an Egyptian engineer, Ibrahim Sayet Hilali, was found yesterday, a day after he was seized by gunmen in Tikrit. Hilali had lived in Tikrit for a long time, police said.
A French aid worker and a German citizen also are being held by kidnappers. In addition, there has been no further word on the fate of an American hostage, Ronald Allen Schulz, after an Internet statement, made in the name of the Islamic Army in Iraq, said on Thursday that his abductors had killed him.
Iraqi officials say the kidnappings may be part of an effort to undermine the elections this Thursday to choose a parliament for the next four years.
US officials have expressed hope that a big turnout among the Sunni Arab minority, the foundation of the insurgency, will help quell the violence so that US and other foreign troops can begin withdrawing next year.
In an interview, the top US commander in Iraq, General George W. Casey Jr., said that based on the assessment of provincial governors, he expected a turnout Thursday of 65 percent to 80 percent, ''except in Anbar," the Sunni province most affected by the insurgency.
''We have seen a history of an increase in attacks heading up to the elections, leading into the referendums in an attempt to create the perception of insecurity to keep the Iraqi people from the polls," Casey said. ''They weren't able to do it in January . . . and they're not going to be able to do it again."