Armed men seized a police station and hostages in Armenia's capital Yerevan on Sunday, killing one police officer in the process before demanding Armenians take to the streets to secure the release of jailed opposition politicians.

Their main demand was to free Jirair Sefilian, an opposition leader whom the authorities have accused of plotting civil unrest. Sefilian was jailed in June over allegations of illegally possessing weapons.

Armenia's security service said one policeman had been killed and two wounded in the violence, but that negotiations were now underway to try to persuade the hostage takers to lay down their weapons.