Prime Minister Abhisit Vejjajiva yesterday sustained minor injuries from attacks by a group of red-shirted protesters at the Interior Ministry, before narrowly escaping through a backdoor.

In the attacks, four men in the prime minister's motorcade were also attacked and wounded, including PM's Secretary-General Niphon Phromphan. Two bodyguards and the driver of Abhisit's vehicle were initially held by the protesters, but later allowed to be taken to hospital.

An unconfirmed report said Abhisit escaped from the compound through a backdoor and his motorcade was used as a decoy to keep the protesters inside the ministry. It is not immediately known how he sustained injuries to his arm.

The mob arrived at the ministry and surrounded the compound before Abhisit and his motorcade left. The protesters then climbed the wall into the compound and stopped two Mercedes vehicles, which were apparently on standby for the prime minister.

The protesters blocked the vehicles and grabbed Pol Sergeant-Major Chanin Singlek and beat him up, before they turned to the other vehicle and did the same to two military officers, one identified as Major Pakorn Somphant, who were inside the car.

The group grabbed a pistol from Pakorn's holster and fired one shot in the air. The pistol was passed on to other protesters and all the bullets were fired in the air. Nattawut Saikua, a protest leader who went to the ministry and later spoke to reporters at the scene, accused Pakorn of shooting at the crowd of protesters, but the major denied it.

Niphon was trapped in his personal BMW, without help or intervention by some 100 security officials stationed in the ministry compound, while the protesters continued smashing his car for about five minutes. Niphon and all three officers were later allowed to be taken to hospitals by the protesters, who had initially stopped ambulances from entering the ministry compound.

Niphon suffered head injuries and broken ribs, Dr Chatree Charoenchivakul, Narenthorn EMS Centre secretary-general, said later.

Nattawut said three red-shirted protesters, including a woman, were shot. His claim could not be independently confirmed.

Abhisit's whereabouts have been kept confidential after his escape. He later said in a phone interview he was fine and the gunshot was accidentally fired during a struggle between the mob and the major.