Federal investigators are offering a $10,000 reward for help in finding thieves who took more than 20 firearms, including machine guns, from a Pittsburgh-area based gun dealer near King of Prussia in Eastern Pennsylvania last night.

The firearms, with a value of $200,000, were stolen from the gun dealer's vehicle in the parking lot of a restaurant, according to Upper Merion Township Police. The dealer, who authorities haven't identified, was traveling back to Pittsburgh after participating in a gun show at the Valley Forge Convention Center.

The dealer has a federal license to sell machine guns, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Anyone with information is asked to call the ATF at 1-800-283-4867 or the Upper Merion Police Department at 610-265-3232.