Members of an Iranian dissident group have been killed at a contested camp in Iraq, according to the Iraqi government and the opposition, although their accounts of the circumstances differ.

The deaths occurred at Camp Ashraf, a Saddam Hussein-era community north-east of Baghdad that is home to about 100 members of the Mujahideen-e-Khalq (MEK), who oppose Iran's clerical regime. The Iraqi government wants to shut the camp and move the occupants out of the country.

A spokesman for the MEK's parent organisation, the Paris-based National Council of Resistance of Iran, alleged that the deaths occurred in a raid by Iraqi security forces. The spokesman, Shahin Gobadi, said some of those killed were found handcuffed behind their backs.

Gobadi said 44 people inside the camp were killed, and he provided photos allegedly from the scene that showed the bodies of several people who appeared to have been killed with gunshots. It was not possible to independently verify the authenticity of the photos.

A police official in Diyala province, where Camp Ashraf is located, corroborated the account of an Iraqi raid on the camp overnight, and said that at least 19 people died. He agreed to speak only on condition of anonymity because he was not authorised to release the information.

Ali al-Moussawi, a spokesman for Iraq's prime minister, confirmed that some camp residents were killed.

However, he said a preliminary investigation suggested they died as a result of infighting between camp residents, and denied that Iraqi forces were involved. Authorities are still trying to determine the number of casualties, he added.

Gobadi dismissed the government spokesman's claim as "preposterous" and "absolute lies".

Iranian state television reported at one point that 23 MEK members were killed by "the Iraqi people and mujahideen". It gave no sources for the information and did not broadcast any footage.

Previous Iraqi raids on the camp, including one in April 2011, claimed dozens of lives.

The acting UN envoy to Iraq, Gyorgy Busztin, condemned the events at Camp Ashraf, but did not assign blame.

"The priority for the Iraqi government is to provide immediate medical assistance to the injured and to ensure their security and safety against any violence from any side," he said.