Police are investigating the possible connection between two gas station robberies that happened just hours apart in Suffolk County.

According to police, the Conoco Gas Station on Middle Country Road in Lake Grove was robbed at 8:45 a.m. Sunday.

Police say a man showed a large butcher knife and demanded cash from employees. Conoco manager Dhan Mahrajan says his clerk backed off after the suspect threatened to stab them.

Footage obtained by News 12 shows the man taking more than $1,300 from the cash register. He then took off.

Mahajran told News 12 that he's glad no one was injured.

Hours earlier, around 1:25 a.m., police say a man with a knife pried open the register and stole the cash drawer at BP Gas on Morris Avenue in Holtsville.

No one was hurt in either incident. The station owner, Ward McAllister, says the drawer had several hundred dollars in it.

Police told News 12 that they believe the two robberies were committed by the same suspect. They say the suspect may have even committed a third knifepoint robbery at the end of last year.

Police say the third robbery took place at a 7-Eleven in Farmingville on Dec. 31 around 1:30 a.m. They say there will be stepped-up patrols around gas stations as a result of the robberies.

Anyone with more information is asked to call Crime Stoppers at 1-800-220-TIPS.