Police are searching for a kitchen-knife wielding robber who they say is terrorizing fast food workers in Nassau County.

According to officials, a man armed with a knife forced a worker to hand over the cash in the register at the Carvel on Peninsula Boulevard in Hewlett Wednesday.

Glen Aleksis, owner of the Carvel, says his son was behind the counter when the knife-wielding suspect demanded money.

"He showed he had a knife, like this, and then he said, 'open up the register,' took the money and walked out," says Aleksis.

Police believe it is the same suspect who robbed another Carvel at knifepoint Tuesday night in North Valley Stream as well as a 7-Eleven, a Subway and several Dunkin' Donuts since the beginning of last month. They say he has struck 10 stores in total in the last six weeks.

Officials say the robbery spree started on March 1 at the Dunkin' Donuts on Lakeville Road in New Hyde Park.

Police say the suspect hangs outside the businesses, waits until there are no customers and then goes inside and demands money.

Surveillance video from one of the previous robberies shows the suspect entering a store. 

Anyone with information is asked to call Crime Stoppers at 1-800-244-TIPS.