BAGHDAD  - Security forces confiscated hundreds of rifles, thousands of rounds of ammunition and other military gear in a crackdown on private security contractors in Iraq, officials said on Saturday.

Police raided three locations in Baghdad on Friday, a week after Iraqi authorities were incensed by a U.S. judge's decision to throw out charges against five Blackwater Worldwide security guards accused of killing over a dozen Iraqi civilians in 2007.

Officials said they are targeting private security companies that are no longer legally licensed to operate in Iraq.

"All those companies with their work permits expired are not allowed to move one meter inside Baghdad, or own one piece of weaponry," Baghdad security spokesman Qassim al-Moussawi said.

He would not reveal how many unlicensed contractors were on the target list, or their names.

Authorities raided the headquarters of a foreign security contractor, whose name could not be immediately confirmed, on Friday night and confiscated 20,000 rounds of ammunition and more than 300 armored shields.

In another location they found 400 rifles, helmets, radio devices and more than 35 vehicles believed to belong to the same company, officials said. No one was arrested.

Private foreign security contractors played a major role in Iraq following the U.S. invasion in 2003, in many cases hired by the United States to guard diplomats and other officials. Iraqis accused them of running roughshod over locals.

For a time, the foreign guards enjoyed immunity from prosecution. That ended with a bilateral agreement that took effect in 2009.

The Iraqi government called unacceptable the U.S. court's December 31 dismissal of charges against five Blackwater guards accused of shooting indiscriminately in a Baghdad traffic circle, and said it is taking its own legal steps against the company, now known as Xe Services.

Major General Hussein Kamal, Iraq's deputy interior minister, denied that the Baghdad crackdown was a reprisal for the Blackwater case. He said the ministry had given a group of security firms ample warning to renew their permits.

"We have closed some of the companies and confiscated their weapons and vehicles," he said, adding, "We are not reacting to the (Blackwater) judge's decision."

(Writing by Jim Loney; Editing by Dominic Evans).