Rejecting an immunity plea of Raymond Davis on Thursday, a court in Lahore has determined that the American CIA contractor does not have diplomatic immunity in the shooting deaths of two Pakistanis.

The decision is a blow to Washington, which insists that the man, Raymond Allen Davis, is considered a diplomat and cannot be prosecuted.

The American contractor, Raymond Davis, 36, shot dead two men in the eastern city of Lahore on January 27.

Earlier on Thursday, the trial for detained US national resumed at at Kot Lakhpat jail.

Heavy security measures were put in place at Kot Lakhpat jail where machine guns were installed on top of water towers inside the jail and concrete barriers were placed on the road leading to it.

Asad Manzoor Butt, a lawyer representing victims in the case, says Davis was not charged during Thursday's hearing.

The next trial court hearing is set for March 8.