NORTHRIDGE (CBSLA) – Authorities are looking for armed robbers who hit at least four 7-Eleven convenience stores across the San Fernando Valley on Friday morning.

The cash robberies occurred in Lake Balboa, Northridge, Chatsworth and Granada Hills within a span of two hours, Los Angeles police said.

In each case there were two suspects, at least one of whom was carrying a semi-automatic handgun. There were no injuries.

The robberies occurred as follows:

12:15 a.m. in the 17200 block of Vanowen Street in Lake Balboa

12:52 a.m. in the 8700 block of Corbin Avenue in Northridge

12:53 a.m. in the 20800 block of Lassen Street in Chatsworth

1:25 a.m. in the 16100 block of Devonshire Street in Granada Hills

Investigators are still trying to determine if all four robberies are connected.

According to security footage, hooded and masked robbers walk up and tell an employee to open a register before pulling out a gun.

Investigators say it’s unclear if the robberies are connected… but detectives are looking into the possibility the suspects are part of a robbery crew. They are also looking into why these 7-11s were targeted.

Lyssa Wright, a customer at 7-11 was there when it happened. “It was shocking, it’s scary, it’s really sad, I grew up out here.”

Anyone with information should contact LAPD.