Los Angeles police are investigating four armed robberies of businesses in the North Hills and Granada Hills areas and looking for any possible links to a string of 7-Eleven armed robberies two days later elsewhere in Southern California that turned deadly.

The Valley area robberies – at two convenience stores and two doughnut shops – took place in a less than two-hour span on Saturday, July 9, and all were in close proximity of one another, the LAPD said. Money was taken from each location but no injuries were reported.

The robberies started at 3:55 a.m. in the 16000 block of Parthenia Street of North Hills, when a man between the age of 25 to 30 wearing a black hooded sweatshirt, a black face covering and dark jeans demanded money from store employees while armed with a handgun, police said. Then at 4:30 a.m., the same suspect robbed a business about a block north in the 16000 block of Nordhoff Street, police said.

In Granada Hills, a business about three blocks north in the 16000 block of Devonshire Street was robbed at 4:50 a.m., according to the LAPD. Then another business was robbed by the suspect about two blocks north in the 16000 block of San Fernando Mission Boulevard at 5:30 a.m., according to police.

They didn’t specify which business was at which address.

The man was not seen on surveillance footage using a car in any of the robberies and police think he may have walked to each location, according to Deputy Chief Alan S. Hamilton.

At a news conference Tuesday afternoon, Hamilton addressed the possibility of a link between those robberies and the six armed robberies of 7-Elevens early Monday, July 11 that left two people dead. The incidents happened in Ontario, Upland, Riverside, Santa Ana, Brea and La Habra and most of them are believed to be connected.

“There’s nothing to specifically confirm (that the investigations are connected) at this second,” Hamilton said in a phone interview Tuesday evening.

He said establishing a link to the Monday spree was difficult because of the suspect’s concealed identity and the poor quality of the surveillance footage in the Valley cases.