Four Kangaroo locations were robbed in the early hours of Sunday, Dec. 23. This location is 6960 Lee Highway.

After a man walked into four convenience stores, brandishing a knife and asking for money, police are still looking for the suspect.

"The four of them were back to back. We feel they are the same suspect," said Chattanooga Sgt. Scott Bales, who oversees the robbery unit.

The man is described as black, between 5 feet 7 inches and 6 feet tall with a dark complexion and thin mustache. Witnesses believe he is in his late 20s or early 30s. He was last seen wearing a black hooded shirt and blue jeans. He fled in a red vehicle, possibly a Chrysler PT Cruiser.

So far, camera footage at stores reviewed by police reveals little identifying information about the knife-wielding man.

"He pulls the hood very tight over his face," Bales said.

In each case, a man entered a store and either went to use the restroom or asked to use it before robbing the clerk. The robber was successful in getting money from three of the businesses. In one case, the clerk ran out the door and he was unable to take anything, Bales said.

The following stores were robbed between 1:35 and 3:45 a.m.:

• 1:35 a.m., Kangaroo, 6960 Lee Highway

• 2:30 a.m., Tiger Mart, 3504 Hixson Pike

• 2:39 a.m., Kangaroo, 5501 Highway 153

• 3:45 a.m., Kangaroo Express, 7020 East Brainerd Road.

Robberies in Chattanooga are on the rise overall compared with last year. In 2011, the department had an unusually low year, recording 385 robberies, compared with 2010 when there were 512.

This year, as of October, investigators already had responded to 402 robberies.

Anyone with any information about the recent holdups is asked to call police at 423-698-2525 or Crime Stoppers at 423-698-3333.