Lawrence Police investigate the Central National Bank branch at 603 W. Ninth Street, Thursday, July 14, 2011. An armed robbery was reported there earlier in the afternoon.

Security cameras at Central National Bank captured these photos of the man who robbed the bank on Thursday.

Security cameras at Central National Bank in Lawrence captured these photos of the man who robbed the bank July 15.

Security cameras at Central National Bank captured these images of the man who robbed the bank Thursday.

Lawrence police were searching Thursday afternoon for a man who robbed Central National Bank, 603 W. Ninth St., and ran south on Louisiana Street.

Officers were called to the bank at 3:25 p.m. Thursday after witnesses inside the bank reported a man entered the building from the south, went to the lobby and demanded money from some tellers.

Lawrence police are working to determine the events and circumstances surrounding the robbery with investigators from the FBI, which is common in bank robberies. Bridget Patton, an FBI spokeswoman, said that the man left with an undisclosed amount of cash.

“He had his right hand in his pocket, indicating a weapon. However, no weapon was shown,” Patton said.

Officers and detectives were canvassing the area south of the bank Thursday afternoon, and detectives were at the crime scene collecting evidence and working to examine surveillance video.

Police described the suspect as a white male, in his mid-20s, about six feet tall, with brown hair, wearing a green cap, blue jeans and a black zip-up coat.

Later in the evening, police released photos of the suspect.

Lawrence Police Sgt. Matt Sarna said officers were unsure if a vehicle was involved in the robbery.

“We have no witnesses at this time who saw any type of vehicle,” he said.

No injuries were reported.

“If people do get robbed by someone wanting cash, we ask them to give them the money and give in to all of the demands that they ask,” Sarna said.

He said police also ask businesses to immediately lock their doors afterward and try to give the best description of the suspect they can.

Anyone with information in the case is asked to call Lawrence police at 785-832-7560 or Douglas County Crime Stoppers at 785-843-TIPS (8477).