Pakistani opposition politician Imran Khan has been arrested after making his first public appearance since emergency rule was declared, police have said.

The former cricketer was detained after going to the University of Punjab in Lahore to address a protest by students against President Pervez Musharraf.

Mr Khan was initially held for an hour by students from the Jamaat-e-Islami party after a confrontation on campus.

On Tuesday, Mr Khan said there should be no negotiations with Gen Musharraf.

Mr Khan joins scores of other more powerful opposition politicians already in custody.

The former cricketer is well known around the world from his sporting days, but his Tehrik-i-Insaf (Movement for Justice) party has little support in Pakistan.

'House arrest'

Witnesses said there were chaotic scenes at the university when Mr Khan arrived to try to address a rally of his student supporters on Wednesday morning.

"I hope to start the movement for the restoration of democracy amongst the student community," he had earlier told the BBC.

"I want the students to be mobilised, as well as the lawyers and the political parties, because it has to be a comprehensive movement against the brute force of a military dictator."

However, a large group of students from the rival Islamist Jamaat-e-Islami objected to his presence at the university and a confrontation developed, according to his spokesman, Seth Niazi.

Mr Niazi said Mr Khan was subsequently locked inside a nearby building for an hour by the rival students before they put him in a van and drove him to police officers waiting at the campus gates.

Later, several Lahore police officials confirmed they had taken Mr Khan into custody.

Mr Khan had been in hiding in Lahore for 11 days after escaping from his home when emergency rule was declared by Gen Musharraf.

On Tuesday, he told the BBC he had agreed with ex-PM Benazir Bhutto, who is under house arrest, that the parliamentary election due to be held by mid-January would be meaningless if the state of emergency were not lifted.

"I am glad that all the opposition parties have come round to our point of view, which is that there should be no compromise with a military dictator," Mr Khan said.

Earlier, Ms Bhutto called for the president to step down, saying the Pakistani people had lost confidence in his ability to steer the country towards democracy.

The BBC's Damian Grammaticus in Islamabad says Ms Bhutto is due to be released in a few days, but Mr Khan, who has consistently taken a tougher line in criticising the president, is unlikely to be released from captivity any time soon.