Iraq 's armed forces moved against a camp holding thousands of members of an Iranian resistance movement that's based in Iraq Friday, killing dozens and wounding hundreds, according to a spokesman for the movement.

It wasn't immediately possible to verify the claims of the People's Mujahedeen Organization of Iran, or MEK, of 31 dead and 300 wounded. Video clips sent out by the MEK's political wing showed armored personnel carriers and military Humvees breaching the perimeter of
Camp Ashraf , apparently in the early hours of Friday morning. Five Iraqi soldiers also were reported injured.

The apparent attack on the camp coincided with a visit to
Northern Iraq by U.S. Defense Secretary Robert Gates, who told reporters U.S. forces were maintaining a "nearby presence" and "may be rendering medical assistance." He said he was unable to confirm the number of casualties.

In a statement, Gates said: "I urge the Iraqi government to show restraint and live up to their commitments to treat Ashraf residents in accordance with Iraqi law and international obligations."

Iraqi military and government officials denied that force weapons had been fired. "One hundred members of the People's Mujahedeen Organization of Iran attacked our security and military forces," said Iraqi government spokesman Ali al-Dabbagh, the Associated Press reported. "Our forces did not use weapons. The situation is calm now."

The leader of the cult-like movement, Paris-based Mariam Rajavi, sent a letter to U.S. President Barack Obama Friday morning saying that six of the dead were women and that the dead were either shot or crushed under vehicles.

In the letter, seen by the Wall Street Journal, Ms. Rajavi held the
U.S. responsible for the safety of the 3,400 people in the camp, based on agreements each signed individually with the coalition forces after the 2003 invasion of Iraq . In those letters, one of which was also seen by the Wall Street journal, the camp residents pledged non-violence in exchange for protection.

"I appeal to you to act upon the
U.S. government's commitments and responsibilities and prevent the continuation of war crimes," Ms. Rajavi wrote in the letter.

In the video clips, MEK members waving sticks and carrying riot shields are seen attempting to force the vehicles to turn back by running in front of them and were met with tear gas. The group named 11 of the purported fatalities and produced a video with their faces when alive, and in some cases dead.

The MEK is an Iranian dissident group that remains on the U.S. State Department's list of terrorist groups, although no armed attack by the group has been recorded since it renounced violence in 2001.

Closing the camp on
Iraq 's border with Iran has long been a top priority for the regime in Iran , and visits by Iranian officials to Iraq routinely include public demands for the camp's closure. While not popular within Iran , the MEK continues to worry the regime. It was the MEK's political wing--the National Council of Resistance in Iran --that first publicly exposed Iran 's nuclear fuel program in 2002. The NCRI has made a series of further revelations about the Iranian program since.

"This is absolutely a bloodbath. These are unarmed people," said Shahin Gobadi, spokesman for the NCRI. He said the Iraqi government was acting under pressure from
Iran , because " Tehran is in a very difficult situation, the uprisings began again and they feel threatened." He was referring to the green movements popular protests in Iran that began in 2009 and reignited amid the recent wave of pro-democracy uprisings in the Middle East .

Camp Ashraf was for years the group's armed training base in Iraq , where the group was sheltered by former President Saddam Hussein. But in the wake of the U.S. invasion of Iraq , the camp disarmed. Originally under the protection of coalition forces after the Iraq invasion, Camp Ashraf has since become a political headache for the U.S. and the Iraqi government. The camp residents have refused to leave and seek asylum outside Iraq .