Violent clashes broke out Thursday in the eastern Pakistan city of Lahore between police and lawyers protesting against the rule of President Pervez Musharraf.

Demonstrators threw bricks, glasses and sticks at police who blocked the path of about 400 lawyers as they tried to march from one court complex to another, according to an Associated Press reporter at the scene.

Some police officers picked up the missiles and threw them back at the lawyers, and used batons to beat several demonstrators who clambered over a gate onto the road.

Four lawyers and three policemen were injured, said Zahid Abbas, a police official, who was bleeding from a wound to his hand caused by a flying stone. At least two lawyers were detained.

Riot police wearing helmets and carrying shields eventually retreated far enough to let the protesters onto the street in front of the district court, but surrounded them on three sides.

The lawyers chanted slogans including "Go, Musharraf, go!" and "Friends of Musharraf are traitors!" and tore down election posters for a prominent Musharraf ally.

Lawyers and judges have been at the forefront of protests against Musharraf because of his campaign against Pakistan's Supreme Court.

Musharraf purged the court after declaring a state of emergency on Nov. 3, just as it prepared to rule on the legality of his victory in an October presidential election.

The court, re-staffed with loyal justices, last week approved his re-election. Musharraf was sworn for a new five-year mandate Thursday, a day after retiring from his dual role as army chief.