Commandos were sent in when negotiations broke down

The three judges were killed by the prisoners as the hostage-takers tried to shoot their way out of the jail in the city of Sialkot, Punjab province, they said.

A number of other judicial officials taken hostage were freed, along with dozens of inmates who were also being held.

Deputy Inspector General of Police Malik Iqbal told the AFP news agency an unspecified number of hostages were also injured in the exchange of fire.

Demands conveyed

The siege had begun earlier on Friday when the five prisoners opened fire on a team of at least 11 judicial officials on a routine inspection of the district jail.

The judges were not hurt at the time but were taken hostage in the women's wing along with up to 50 inmates, mostly women.

Four hostages were quickly freed to convey the prisoners' demands.

The prisoners, who were all serving at least 25 years for crimes including kidnapping, had called for a van, arms and safe passage out of the jail, said Mr Iqbal.

Efforts to negotiate failed and when the inmates threatened to kill the judges they were still holding, the authorities decided to send in the commandos.

The judges were thought to be district-level officers rather than high court judges.

Possession of arms by prisoners has become increasingly common in Pakistani jails.