Turkish police have raided the offices of the opposition Zaman newspaper, hours after a court ruling placed it under state control.

Police entered the building in Istanbul late on Friday, firing tear gas at protesters who had gathered outside.

Zaman is closely linked to the Hizmet movement of influential US-based cleric Fethullah Gulen.

Turkey says Hizmet is a "terrorist" group aiming to overthrow President Recep Tayyip Erdogan's government.

Mr Gulen was once an ally of Mr Erdogan but the two fell out.

Many Hizmet supporters have been arrested.

The government in Ankara has come under increasing international criticism over its treatment of journalists.

The court ruled on Friday that Zaman, a high-circulation newspaper, should now be run by administrators. No explanation was given.

Later, hundreds of Zaman supporters gathered outside the newspaper's offices to protest at the state takeover. One held a placard saying, "We will fight for a free press."

Police used water cannon and tear gas to disperse the protesters.