The finding comes as the military is reportedly investigating allegations that soldiers disobeyed top-level orders and opened fire on pro-democracy protesters with live rounds instead of only plastic bullets.
Fragments from "high-velocity type" bullets were found in the bodies of seven students killed during protests and rioting in which up to 16 people died, said Dr. Mun'im Idries of state-run Cipto Mangunkusumo Hospital, where post mortem examinations were carried out.
"We found that the seven students were killed because of the high velocity of the bullets that hit them," Idris told The Associated Press.
Budi Sampurna, head of the hospital's forensic department, said the fragments had been handed over to military investigators.
Armed forces chief Gen. Wiranto ordered an investigation to determine how the deaths occurred despite live ammunition being banned during last week's clashes, said Wayan Karya, spokesman for the political and security affairs minister.
"The investigation aims to find out exactly what went wrong," Karya was quoted as telling reporters by The Indonesian Observer.
"We want to find out why, despite the fact that live ammunition was expressly prohibited by military commanders, one post mortem did locate a bullet embedded in the body of a victim," he said.
Meanwhile angry students punched and kicked a Cabinet minister after invading a provincial airport where government officials were holding a meeting on Thursday, the newspaper Kompas reported.
It said bodyguards rescued Agriculture Minister Soleh Salahudin from a mob of students in Padang, about 1,000 kilometers (600 miles) northwest of Jakarta.
The minister later met with the students, who demanded the military be removed from government and that Wiranto resign.
Students kept up their protests on Friday.
Fresh flowers were laid in the street outside the Atma Jaya university, the scene of the worst violence one week ago, during a commemoration rally attended by about 1,500 students, families and supporters.
Other protests, numbering several hundred students each, marched peacefully elsewhere in Jakarta, demanding Wiranto's resignation and greater political change. All protests were watched by police.
About 30 members of the Front of Indonesian Women Action were blocked by soldiers more than 100 meters (yards) from the defense ministry.
In Surabaya, the second largest city, several hundred protesters marched on a government building demanding an inquiry into Suharto's wealth.
A visiting U.S. official on Friday urged the government to push ahead with reforms, including investigation of human rights abuses and efforts to scale back the military's prominent role in politics.
"One way that a society can gain confidene in itself... is to have a full and fair examination of (past) human rights abuses," said Harold Koh, U.S. assistant secretary for democracy, human rights and labor.
Human rights groups say as many as 16 people, including students and soldiers, were killed in last week's confrontations. Police say 13 people died. Hundreds were injured.
Opposition figures and students claim the military provoked much of the violence.
President B.J. Habibie has accused some opposition groups of orchestrating the protests as part of a plot to overthrow his 6-month-old government.
Police said Friday 70 people would be tried on charges related to looting which was triggered by last week's student clashes.
Indonesia is enduring its worst economic turmoil in three decades. Discontent over inflation and joblessness helped spark the bloody May riots which helped forced Suharto out and in which 1,200 people were killed.
Kompas reported Friday that offices and cars were burned in two separate riots in South Sumatra province, northwest of Jakarta.