Mark Landler, Jakarta, Indonesia – Security forces killed at least four students and injured more than 20 others when they opened fire on a demonstration that had spilled from a college campus onto a major highway here.

According to several witnesses, the violence started after a peaceful day of demonstrating by the students, who sang songs and called for the resignation of President Suharto. But when they refused to return to campus, police clubbed them with truncheons and shot into the crowd.

Tuesday's unrest was the most serious in Indonesia in three months of almost daily student protests. And it erases any presumption that the anti-government movement is limited to politically radical campuses in the hinterlands. These clashes occurred at the University of Trisakti, an elite private college in the shadow of Jakarta's gleaming financial district, where many senior government and military officials send their children.

"We were running when we heard shots," said a 22-year-old management student, who declined to give his name. "I saw my friend get shot in the neck. I also saw a girl fall down in front of me and get kicked in the head."

Riot police swarmed outside the campus gates on Tuesday night, while inside, hundreds of students gathered in darkened courtyards, warning that police snipers were lurking on the rooftops. An administration building was converted into a makeshift first-aid center, with bloodied gauze and bandages littering the floor.

In a sign of how organized the demonstrators have become, they had compiled a list of dead and injured students within an hour of the attack. Still, as the students milled around in the stifling night air, heavy with the fumes of tear gas, most seemed dazed by the sudden eruption of violence.

"They shot onto my campus," said a student named Awing, in a disbelieving tone. He, like many others, insisted that the protesters had not provoked the police before they opened fire. But one student said that just before the shooting, the riot troops cocked their rifles, prompting a hail of taunts from the students.

On the highway next to the campus, which had been occupied earlier in the day by cheering students, traffic inched over rocks and other debris and past a long line of troop transports and armored vehicles with water cannon. The road is one of Jakarta's most heavily-traveled, connecting the city center to the airport. Jakarta was not the only place where student protests turned violent on Tuesday. In Bandung, a college town 75 miles southeast of Jakarta, police clashed with 600 students, firing shots into the air and clubbing several with truncheons. And in Kupang, a city in Timor 1,150 miles east of the capital, police fired tear gas to disperse a crowd of 300 student demonstrators.

The protests have been gathering force since early last week, when the Suharto government announced that it would raise the price of fuel and electricity by as much as 70 percent. Although the price increases fulfill Indonesia's agreement with the International Monetary Fund, students have decried them as unjust.

Suharto has been out of the country since Saturday, attending a summit meeting of 15 developing nations in Cairo. On Monday, Suharto said Asia's deepening economic crisis "could trigger a series of social problems, including the further spread of poverty, a rise in crime, and political instability."

Before his departure, Suharto warned in televised remarks that the police and military would crack down on anyone who threatened Indonesia's "national stability." People here said that Suharto's decision to leave the country during the growing turmoil underscored his confidence in his position.

But political experts have also said that the student movement would reach a flash point if security forces fired on the students, or if the violence spread to the capital. A growing number of nonstudents have already joined demonstrations, and witnesses said outsiders threw rocks at the police in Tuesday's protest.