Haiti's interim government has opened an investigation into accusations that police executed 13 people in a Port-au-Prince slum.

The killings allegedly took place Tuesday in the Fort National slum, a bastion of support for ousted President Jean-Bertrand Arisitide.

Witnesses say men in police uniforms forced victims to lie on the ground and then shot them.

Police officials deny the accusations, suggesting the executions were carried out by armed gangs.

Haiti's capital, Port-au-Prince, has been wracked by clashes between supporters and opponents of ousted president Jean-Bertrand Aristide. At least 75 people have been killed in the violence, which began in late September.

Some information for this report provided by AP.