YEREVAN, Armenia -- A mediator in the police hostage standoff in the Armenian capital has told local media that the last two captives have been released.

The standoff began July 17 when armed men stormed a police station, killing one officer and taking others hostage. They are demanding the release of an opposition figure who was arrested last month.

The Armenpress news agency says Vitaly Balasanian, a parliament member who has been a messenger between authorities and the gunmen, said the last hostages -- the deputy police chiefs for the country and for the capital ---- were released Saturday afternoon.

Two other policemen were freed earlier in the day, the country's national security agency said.

Balasanian said the releases came after an agreement to establish a media centre near the standoff site was fulfilled. The intent of this apparently is to allow the gunmen enhanced opportunity to draw public attention to their demands.

It was unclear if authorities would aim to eventually arrest the gunmen.