YANGON, Myanmar - Myanmar's military junta has detained at least 63 activists who protested massive fuel-price hikes, state media reported Saturday as the government pursued its clampdown on the increasingly daring demonstrations.

Thirteen people arrested Tuesday were from the pro-democracy 88 Generation Students group and were "being interrogated" for allegedly undermining the government, colluding with insurgent groups and harming the community peace, the state-controlled New Light of Myanmar newspaper said. The activists could face up to 20 years in jail.

Myanmar's ruling junta has been widely criticized for human rights violations, including the 11-year house arrest of opposition leader and Nobel Peace Prize laureate Aung San Suu Kyi. The junta tolerates little public dissent, sometimes sentencing activists to long jail terms for violating broadly defined security laws.

But people in the impoverished country have been angry at the military government's decision to double fuel prices at state-owned gas stations earlier this month, prompting the recent displays of public opposition.

Peaceful protests have been taking place since Sunday, mainly in the country's largest city of Yangon. But Yangon was quiet Saturday, with pro-junta supporters and plainclothes police deployed throughout the city to prevent protests. Trucks stood ready to take demonstrators away.

Eight people were arrested in Yangon as they marched in a protest Wednesday, the newspaper said. The rest were picked up in the same city Thursday and Friday ahead of other planned rallies.

Nyan Win, a spokesman for Suu Kyi's National League for Democracy party, said Saturday the eight protestors detained Wednesday had been released, but that the fate of the others was unknown.

Although the junta quickly broke up burgeoning protests Friday, the defiant demonstrators could claim a partial victory after the government ordered some bus companies to lower fares that were raised because of the higher fuel prices.

The United States, France, Britain and several international human rights groups have called on the junta to ease its repressive activities and free political prisoners. U.N. Secretary-General Ban Ki-moon urged Myanmar's government to exercise restraint in its response to the demonstrations.

Economic dissatisfaction sparked the country's last major upheaval in 1988 when mass demonstrations broke out seeking an end to the military rule that began in 1962. The protests were violently subdued by the army with hundreds, perhaps thousands, of people killed.

The current protests are nowhere near the scale of the 1988 events, but the junta appeared to be taking no chances in trying to clamp down on the demonstrations.

The military rulers held a general election in 1990, but refused to honor the results when the National League for Democracy won in a landslide.