WASHINGTON: Protesters ignored curfew in a Midwestern US town on Sunday to protest the shooting death of an unarmed black teenager by a white police officer.

The protests forced the US federal government to order a third autopsy of the teenager, Michael Brown, to determine the cause of his death.

In the town of Ferguson in Missouri police extended the curfew for a second day and urged protesters not to defy it. Police have arrested seven people for curfew violations while a mysterious gunman shot a protester.

Police said the protester was in a critical condition.

The curfew was imposed after days of protests over the Aug 9 shooting.

In Washington, US Attorney General Eric H. Holder instructed the Department of Justice to have an additional autopsy performed by a federal medical examiner.

The decision, announced on Sunday afternoon, indicates that the federal government is not satisfied with the probe conducted by local authorities.

Officials in Washington said the federal investigation would focus on determining if police had violated civil rights while shooting the unarmed teenager who made no attempt to harm the officer, Darren Wilson, who shot him.

“This independent examination will take place as soon as possible,” Mr Holder said. He said he had ordered the additional autopsy “due to the extraordinary circumstances involved in this case and at the request of the Brown family”.

A spokesman for the Missouri State Highway Patrol, Al Nothum, urged protesters to remain peaceful and not throw stones at police.

“If they’re throwing tomatoes at us, we’re not going to use gas. But if they’re throwing rocks, we’ll escalate that. We need to meet force with force,” he said.

On Saturday, local officials released a video which allegedly showed Michael Brown robbing a convenience store shortly before the shooting.

US federal officials said that they had repeatedly urged local officials not to release the video as it might further inflame tensions in the city. But the local officials ignored the plea.

Published in Dawn, August 18th, 2014