PORT-AU-PRINCE, Haiti (AP) _ University students and government supporters hurled rocks at each other Friday in clashes that left at least 24 people injured, including two university officials.

The students, who were demonstrating to demand President Jean-Bertrand Aristide step down, were met by groups of government supporters in downtown Port-au-Prince. Police fired warning shots to disperse the crowds.

Journalists saw at least six people shot and wounded, including one Aristide supporter and five students. It was unclear who had fired the shots, and the wounded were taken to hospitals.

Meanwhile, Aristide supporters ransacked two university buildings, witnesses said. Several men beat journalist Rodson Josselin of the Haiti Press Network with sticks, bloodying his arm.

University Rector Pierre-Marie Pacquiot went to negotiate with students holed up inside the walled Human Sciences College. While there, journalists saw Aristide supporters break a hole in the wall and beat students.

At least 14 people were injured, including the rector and vice rector. The rector was beaten in both legs with an iron bar, said Vice Rector Wilson Laleau, who suffered minor injuries.

The violence, which underlined growing tensions in the poorest country of the Americas.

``This is the last day that we'll let them demonstrate against our president,'' said Robens Bellefleur, 20. ``We voted him into office.''

Tensions have grown in Haiti since flawed 2000 legislative elections that the opposition charged were rigged. The opposition refuses to participate in fresh elections unless Aristide steps down, but the embattled leader says he will serve out his term until 2006.

``No one in civil society is spared by the generalized disorder spawned by Aristide's bloody regime,'' said Herve Saintilus, president of the Federation of Haitian University Students.

As gunshots, chanting and the sound of falling rocks rang out on Friday, church hymns from nearby churches reverberated in a surreal symphony in downtown Port-au-Prince.

Anti-government demonstrations have increased recently, drawing student groups, the opposition and civic organizations.

About 200 students marched through the capital on Wednesday, waving placards and painting walls with anti-Aristide slogans. A small group of Aristide supporters pelted the students with rocks.

Last week, at least four anti-government protesters were injured when Aristide supporters blocked their march near the downtown National Palace. The president's backers threw rocks and splashed the protesters with a stinging potion of poison ivy steeped in water.