The West Yorkshire Police in connection with firearms offences arrested two more men. They are being held for questioning in Birmingham, reportedly about links with men involved in the hold-up that led to the killing of Pc Sharon Beshenivsky.
The arrests came a day after hundreds of people paid silent tribute to Pc Beshenivsky as her funeral was held at Bradford Cathedral. The 38-year-old was killed as she investigated an armed robbery at Asian-owned Universal express Travel Agents in Morley Street, Bradford, on November 18.
Yusuf Jama, 19, a Caribbean and 24-year-old Muzzaker Imtiaz Shah of Pak-origin are due to face trial in June, charged with Pc Beshenivsky's murder. Police are still looking for Jama's 25-year-old brother Mustaf in connection with the shooting.
He is believed to have links with Sheffield, Birmingham, Coventry and Leicester, although police said he could be anywhere in the country.
Rewards totalling £90,000 are being offered for information leading to the arrest and conviction of the people behind the crime.