Detectives were last night continuing to hunt for two men suspected of murdering Pc Sharon Beshenivsky as a third remained in custody.

Mustaf Jama, 25, and Muzzaker Imtiaz Shah, 24, were still on the run, nine days after Pc Beshenivsky was shot dead and Pc Teresa Milburn wounded while investigating a robbery at a Bradford travel agents.

On Friday, police released pictures of the three men, said to have been living in London, and appealed for the public's help in catching them.

Yusuf Jama, 19, was arrested when police swooped on a house in inner-city east Birmingham on Saturday morning.

He was last night being quizzed by detectives at an undisclosed West Yorkshire police station on suspicion of murdering Pc Beshenivsky, 38, the attempted murder of PC Milburn, 37, and the robbery of the travel agents.

Jama was originally arrested at the weekend in connection with an unconnected alleged serious sexual assault, West Midlands Police said last night.

Nine other men who were arrested after the alleged assault, on a woman at a premises in Bowyer Road, Saltley, remain in custody.

The property where the arrests were made has been sealed off and is undergoing forensic examinations, a police spokesman said.

witnesses described the scene as plain-clothed officers descended on the three-bedroomed terrace house.

They said between four and eight people of Somali appearance were brought from a house, in handcuffs covered by blankets. Other witnesses reported seeing as many as 15 police vans blocking the quiet one-way street as the arrests were made.

Father-of-seven Moham-med Khan, 36, who has lived in the street for 33 years, said the people in the property had been living there for about six weeks.

He said Jama was one of three men arrested at the same time. A fourth man was taken out of the property 20 minutes later.

Other witnesses described seeing Jama being brought out of the house wearing a long, traditional Somali dress.

Postman Mohammed Ali, 29, who lives a few doors away from the property where the arrests were made, said that when he returned from work at 4am, the street was full of police.

"There were a number of police cars outside and the front door of the house was open," he said.

Other residents of Saltley - a large ethnic minority area - described hearing a police helicopter overhead in the early hours of Saturday.

A West Yorkshire Police spokesman said: "The man arrested in Birmingham remains in custody in connection with the murder of PC Sharon Beshenivsky and the attempted murder of PC Teresa Milburn."

Pc Beshenivsky left a husband, three children and two step-children. Her youngest child, Lydia, was celebrating her fourth birthday on the day her mother was shot.

Pc Milburn was released from hospital a week ago after treatment for a gunshot wound to the shoulder.

Five Somali men, and a woman, arrested in London in the aftermath of the shooting, were released without charge.

The men were all bailed pending inquiries. The woman was freed without charge.