Poddala Jayantha is a prominant campaigner for media freedom

Poddala Jayantha received head and leg injuries in the attack near his home in the Colombo suburb of Nugegoda.

Mr Jayantha campaigns for media freedom and is seen by government supporters as an opponent of the authorities.

Critics in Sri Lanka's local media have come under extreme pressure in the past few years. Several independent journalists have been killed.

Mr Jayantha, the general secretary of the Sri Lanka Working Journalists Association, was kidnapped on Monday while he was walking near his home on the outskirts of the capital.

BBC correspondents say he was named by government politicians as an anti-government campaigner who had been instrumental in tarnishing the name of the government.

Threats

As a result of earlier threats and intimidation - which included an armed group trying to kidnap him from his residence - Mr Jayantha spent a brief period abroad, returning to Sri Lanka only a few weeks ago.

Dr Hector Weerasinghe, director of Colombo General Hospital, told the BBC the journalist had suffered injuries to the head and legs.

The attackers shaved parts of his head and the beard as a part of the attack.

Reports say his injuries are not life-threatening.