D.C. police barricaded a three-block area in Southeast for two hours last night to look for a man who shot at, but did not injure, a 7th District officer participating in an undercover narcotics operation.

Shortly after 7 p.m., an undercover officer whom police declined to identify arrested two men in the 3300 block of 14th Place SE.

Police said the men had just sold the officer drugs, and as he arrested them he was shot at by a third man who then fled.

Police said the gunman fired at the officer's left hip, but they said the bullet ricocheted off his handcuffs.

A shot fired by the gunman also struck one of the arrested men, wounding him in the buttocks. Charles Lawton, address unknown, was reported in serious condition last night at Greater Southeast Community Hospital. Lawton was arrested on undisclosed narcotics charges.

"We had undercover officers from the 7th District out here, and they made a buy," said Assistant Police Chief Isaac Fulwood. "And right after that happened, a man jumped from a basement and started shooting."

Dozens of police cars, along with emergency response teams and fire companies, responded to the scene.

About 9 p.m., after searching the area bordered by 15th, Congress and Savannah streets, heavily armed police went inside an apartment building where they suspected the man was hiding. Only a handgun was found, police said.

Fulwood said that they have identified a suspect in the shooting and that an arrest warrant is likely to be issued today.