BAGHDAD, Iraq, AP – The bodies of two American service members missing since a helicopter crash this week were found west of Baghdad, officials said Friday, while gunmen loyal to a radical Shiite cleric torched an office of the Iraqi president’s Kurdish party.

About 50 gunmen in the northern city of Kut stormed the office of the Patriotic Union of Kurdistan, headed by President Jalal Talabani, beat up the guards and set the building on fire, said police Lt. Othman al-Lami. The attackers accused the party’s official newspaper of criticizing Shiite cleric Ayatollah Mohammed al-Yacoubi.

The raid in Kut was another demonstration of Iraq’s sectarian and ethnic divisions that have exploded into violence, mostly between Shiite and Sunni Arabs. It came a day after a suicide bomber killed 35 people in front of Iraq’s most sacred Shiite shrine, the Imam Ali mosque in Najaf.

The U.S. military said the bodies of two American service members missing since a UH-60 Blackhawk helicopter crashed Tuesday have been found. The helicopter crashed in an undisclosed body of water during a routine flight in Anbar province west of the capital, and divers had been looking for the two Americans, U.S. officials said.

Four others were injured in the crash, which was not believed to have been caused by hostile fire. The military did not say when or where the bodies were found.

The deaths raised to 2,597 the number of U.S. military personnel who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

Pamphlets distributed by the attackers in Kut said the Kurdish newspaper accused al-Yacoubi of trying to “ignite a war between the Arab Shiites and Kurds” by claiming that Kurds are targeting other ethnic groups. The largely Sunni Kurds are a separate, non-Arab ethnic group.

The attackers fled after seizing three AK-47 rifles from the guards, al-Lami said. There were no officials in the office during the early morning raid.

In a statement Friday, Talabani acknowledged that some of the phrases used in his party newspaper’s article were “inappropriate … despite the bitterness” he and other Kurds felt over al-Yacoubi’s statement. He said he was not aware of the article’s contents until it was published.

Al-Yacoubi, the spiritual leader of the Fadhila, or Virtue, party, which is part of Prime Minister Nouri al-Maliki’s Shiite alliance, was not immediately available for comment.

However, Fadhila is demanding an official apology from the Patriotic Union of Kurdistan, said party spokesman Sabah al-Saiedi. Al-Yacoubi is urging his followers not to resort to violence, al-Saiedi said, after a party delegation met Friday with Talabani.

Iraq’s rising sectarian and communal violence is claiming about 1,000 lives every month in the Baghdad area alone, raising fears of all-out civil war.

A Sunni extremist group, Jamaat Jund al-Sahaba or Soldiers of the Prophet’s Companions, claimed responsibility for Thursday’s bombing of the shrine.

In a statement posted on an Islamist Web site, the group warned that “our swords are capable of reaching deep in your regions” and accused Shiites of killing Sunnis.

Gunmen on Friday shot and killed three people in Baghdad and one in the northern city of Mosul in separate incidents, police said, and three unidentified bodies were found in Baghdad.