Armed men broke into three houses in the Bethesda-Chevy Chase area early yesterday morning and took money and jewelry from frightened residents, according to Montgomery County police. The robbers are believed to be the same pair who robbed three county houses last week and beat one of the elderly residents, police said.

"They the robberies all have the similar characteristics," said Sgt. Harry Geehreng, county police spokesman. "They've changed the pattern -- now going to early morning. But I'm sure . . . the sequence this morning was committed by the same pair."

About the same time yesterday, police reported that a car was stolen in the area and may have been used by at least one of the robbers.

The robberies, which started at about 5 a.m., followed the pattern that was set last week and which investigators said is linked to another three robberies earlier this year. In all of the incidents, the robbers have taken only cash and jewelry, broken in through windows or glass doors, ransacked the houses and forced occupants to lie on the floor, or in bed, with their heads covered, according to police.

An elderly Silver Spring woman was brutally beaten and another man living across the street was knocked down by intruders on April 23, but none of the other victims has been hurt.

The first predawn robbery yesterday was in the 3700 block of East West Highway. The intruders ordered the woman living there and her 16-year-old daughter to lie in bed while they ransacked the house.

Shortly afterward, a Montgomery County police officer stopped two men in a Volkswagen that was reported stolen in Virginia. The men fled on foot, Geehreng said, and are now believed to have been involved in the robbery.

One of the two, according to Geehreng, then hit a second house, in the 7200 block of 45th Street. Again, the residents were told to lie in bed while the man looked for valuables. The man took car keys from that house but left the cars, police said.

From there, Geehreng said, the man went to the 4400 block of Bradley Lane, where a 1973 yellow Oldsmobile was stolen.

The same man 15 minutes later broke into a third house in the 5200 block of Massachusetts Avenue, near the District line, Geehreng said.

Police have not located the yellow Oldsmobile, according to a police spokesman.

Last week, Montgomery police said they are seeking a meeting with investigators in Virginia, the District and Prince George's County to determine if the robbery pattern extends beyond the county. But yesterday Geehreng said work among the jurisdictions has remained at an informal level while the investigation continues.