Roadside bombs killed two American soldiers in northern Baghdad (search) and ignited a train carrying fuel in the south of Iraq's capital, killing two Iraqis and wounding six others, officials said Thursday.

The bombing that killed the two U.S. soldiers came Wednesday during a patrol by soldiers assigned to the Army's Task Force Baghdad (search), the military said on Thursday. Another U.S. soldier was wounded.

Their deaths brought to three the number of American soldiers killed in central Iraq (search) on Wednesday; seven have been killed since Sunday night. In the other Wednesday attack, a roadside bomb killed an American soldier and wounded five others in Samarra, 60 miles north of Baghdad, the U.S. command said. On Sunday, four American soldiers from Task Force Baghdad were killed when their vehicle ran over a roadside bomb in southwest Baghdad.

As of Wednesday, at least 1,782 members of the U.S. military had died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

On Thursday, a train carrying fuel exploded into flames when it was hit by a roadside bomb in southern Baghdad, killing two people and wounding six others, police said.

The attack, which sent a massive cloud of smoke over the southern part of the city, occurred in the southern neighborhood of Dora, an area where insurgents are known to be active, police Lt. Thaer Mahmoud said.

The bomb appeared to have targeted a nearby police commando checkpoint, Mahmoud said. One of those killed and four of the injured are security force members, he said. The rest were civilians.

It wasn't clear if the train, which was heading south, was also the target.

Most of the wounded suffered serious burns, Thaer said.

The violence came a day after Iraq's most feared terror group said it killed two kidnapped Algerian diplomats because of Algeria's ties to the United States and its crackdown on Islamic extremists.

The diplomats' deaths brought to three the number of foreign envoys reported killed this month as part of a militant campaign to isolate Iraq's embattled government within the Arab and Muslim world. Two other apparent kidnapping attempts against diplomats were foiled.

Algeria opposed the U.S.-led invasion of Iraq, although it has in recent years become a close U.S. ally, particularly in investigating and arresting Islamic extremists. Al-Qaida in Iraq, led by Jordanian militant Abu Musab al-Zarqawi, linked the killing of the diplomats to the Algerian crackdown.

Algeria's chief envoy Ali Belaroussi and fellow diplomat Azzedine Belkadi were slain because their government represses Muslims "in violation of God's will," said a chilling Internet statement posted in the name of al-Qaida in Iraq.

The statement provided no photographic evidence of the deaths, and the statement's authenticity could not be confirmed.

Belaroussi, 62, and Belkadi, 47, were dragged from their cars and kidnapped at gunpoint July 21 in Baghdad's upscale Mansour neighborhood. They appeared — blindfolded and in captivity — in a video posted Tuesday on the Internet.

The Bush administration has been eager to maintain political momentum in Iraq, hoping a broad-based government can lure Sunni Arabs guerrillas away from the insurgency. A key step in that strategy is a new constitution, which is to be completed by Aug. 15 and presented to the voters in a referendum two months later.

On Wednesday, Defense Secretary Donald H. Rumsfeld came to Baghdad to urge the Iraqis to finish the draft charter on time. "People are simply going to have to recognize that (in) any constitutional drafting process, compromise is necessary. It's important. It's understandable. It's the way democratic systems work," he said.

In other developments:

• The electricity ministry said six attacks in the last 10 days on the power grid has led to a reduction in the electricity supplies to Baghdad and nearby southern provinces, according to government newspaper al-Sabah. Power in Baghdad is down to a half an hour of electricity followed by a six-hour blackout.