HARRIS COUNTY, Texas -

Three men are on the run, accused of being part of two separate dollar store robberies.

Investigators say the first robbery happened at the Family Dollar store on Veterans Memorial earlier Monday. Deputies say the men then headed down the street to the Dollar General store.

At the Family Dollar store, police say the robbers found a woman hiding in the back of the store with her child and snatched her purse. Cigarettes and cash were stolen from the other store, according to a source.

The suspected thieves were chased by police before their vehicle drove into a pond on 503 West Road, according to  authorities. The shallow pond is right in front of an apartment complex.

Divers spent a few hours in the water searching for evidence before a tow truck pulled the car out of the pond. A gun was recovered in the water and a cell phone and a mask were found in the vehicle.

Police say they have one suspect in custody, but three more are on the loose.

During the suspect search, two Aldine ISD schools -- Gray Elementary School and Stehlik Intermediate School -- were locked down. Those lockdowns were lifted at around 1:45 p.m.

Earlier Monday afternoon, SWAT surrounded an apartment in which police believe the suspects had barricaded themselves, but there was no one there.