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Police are searching for whoever held up four Subway restaurants in the San Fernando Valley in the past four days, including the most recent incident which occurred in Porter Ranch Thursday night.

Thursday’s robbery in the 19000 block of Rinaldi Street occurred about 10 p.m., Los Angeles Police Department Officer Lopez said.

Investigators say one robbery has taken place each night since Monday.

Monday’s robbery occurred at a Subway in the 8600 block of Lindley Avenue in Northridge.

On Tuesday, a Subway in the 9000 block of Balboa Boulevard in Granada Hills was struck.

And on Wednesday, authorities say the Subway in the 11800 block of Balboa Boulevard in Northridge was also robbed.

Police are not sure if the same man robbed each location but say it is possible.

All of the robberies occurred about 10 p.m. with the intruder being described as a Hispanic man between 30 and 50 years with a handgun.

Investigators are working to gather surveillance videos from each store.