Two women in Pittsburgh dressed as ninjas and carrying swords were videotaped robbing a gas station, according to investigators.

Detectives said the women entered a Richland Township Sunoco at the intersections of Route 910 over the weekend and began waving swords and at least one dagger.

They tied up a clerk at the business before targeting items.

"They were all covered in black and carrying swords, so yeah, it does appear like they were dressed like ninjas," Northern Regional police Chief Robert Amann said.

The women were videotaped dumping cigarettes into a garbage bag before fleeing, officers said. They also stole some lottery tickets.

Detectives said they were concerned about how the crime was committed.

"Swords, daggers or whatever they were carrying could have been used to seriously harm our victims," Amann said. "So, it is a very serous crime."

Amann said the ninja-type robbery has not been seen before.

"Being possibly females and also being armed with swords we very seldom see that sort of weapon used in robberies," Amann said.

Police said they hope some of the women's gestures while in costume generate leads in the case.

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