MEXICO CITY (AP) _ Opponents and supporters of leftist presidential candidate Cuauhtemoc Cardenas clashed Thursday at a Mexico City university during a campaign appearance.

There were no reports of injury as students still angry over the handling of a strike at the National Autonomous University last year threw rocks and eggs after massing on the main plaza.

Cardenas, Mexico City's mayor at the time and now running for president, told the crowd that he was also disappointed in the university's handling of the strike and asked both sides to seek a solution.

``It hurts and irritates me that university authorities have proven to be insensitive, incapable and unyielding,'' said Cardenas.

Initially supportive of the 10-month strike, Cardenas backed away as more radical students gained control. Strike leaders accused Cardenas of betraying leftist ideals.

Cardenas, who is running a distant third in opinion polls, promised convert Mexico's largest school into a ``public university of excellence'' if elected president.

``One can differ, it's valid, but in the a university this must be valued, everyone should have the opportunity to express themselves,'' he said.

But his remarks failed to convince some in the crowd. One person hurled a small explosive near the empty stage and Cardenas opponents rushed at his supporters.

Some members of the crowd burned Democratic Revolution Party flags in a bonfire, while others began throwing rocks and eggs or brandishing broken sticks. Some students were seen with bloody noses.

Supporters and opponents of Cardenas accused each other of provoking Thursday's violence.

Cardenas, who is making his third attempt at the presidency, had accepted an invitation from moderate faculty and students to speak at the university, 10 days before the July 2 election.

There were no major confrontations leading up to the event, attended by an estimated 30,000 people. During his speech, supporters jammed onto a low rooftop, while dissenters gathered nearby.

The strikers' occupation of the university, which ended in February, began as a protest against tuition increases but later became a platform to denounce free-market government policies.