A mediator in the police hostage standoff in the Armenian capital is telling local media that two hostages have been released and that a tentative agreement on freeing the other two has been reached.

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 go-between between authorities and the gunmen, said that two of the hostages were released Saturday. He also said the other two, who include Armenia's deputy police chief, would be released if an agreement to establish a media center near the standoff site was fulfilled.