Myanmar activists vowed to keep up the pressure on the government despite a violent crackdown on their student-led protests that sparked international alarm, as authorities continued to hold dozens of demonstrators.

Police armed with batons beat protesters at two recent student-led rallies calling for education reform, in violent scenes that have drawn comparisons to the tactics used under the former junta.

Dozens of Myanmar activists shouted messages to relatives from packed prison vans outside a court Wednesday after being detained in a violent student protest crackdown that sparked international condemnation and fears of a return to junta-era repression.

Student-led rallies calling for education reform have twice been brutally suppressed in recent days, drawing fierce criticism from overseas and Aung San Suu Kyi's opposition, which said the tactics echoed those used under the former military government.

The EU criticized Myanmar on Tuesday after baton-wielding police dispersed a student rally and arrested dozens of protesters in a crackdown which has raised fears of a return to junta-era repression.

The 28-nation bloc also defended its 2013 decision to launch a 10-million-euro program to train Myanmar police in dealing with demonstrations, saying it was part of efforts to support reform.

China on Tuesday warned over escalating violence between Myanmar's military and rebel forces after a civilian home was hit by shelling from across the border, apparently for the first time in the current unrest.

Beijing has previously warned of a threat to border stability after the dramatic upsurge in ethnic conflict in the remote Kokang region in Myanmar's northeastern Shan state.

Myanmar arrested 127 protesters when baton-wielding police dispersed a student rally Tuesday, as the second crackdown in days deepens fears that authorities are returning to the repressive reflexes of the junta era.

Two large truckloads of protesters were taken away after riot police violently broke up the rally in the central town of Letpadan, according to an AFP reporter on the scene, ending over a week of stalemate between the authorities and students calling for education reforms.

Myanmar authorities have defended a crackdown on a Yangon rally that saw police and men in civilian clothes beat unarmed protesters, as security forces made fresh arrests on Friday.

In a defiant statement as authorities launched a third day of action against several demonstrations, the state-run Mirror newspaper said police acted legitimately to disperse a rally on Thursday in the heart of Yangon.

Security forces attacked and detained around eight Myanmar activists protesting in downtown Yangon, campaigners said Thursday, in a surge in tension over spreading student rallies calling for education reforms in the former junta-run nation.

Dozens of demonstrators were sent scattering after they were set upon by uniformed police officers backed by plain clothes men wearing red armbands who attacked the group with batons, according to witnesses and campaigners.

Student protesters calling for education reform said Tuesday that riot police have ordered them to disperse within hours after surrounding them near a monastery in central Myanmar.

Some 300 young activists -- many sporting bandanas with the fighting peacock symbol of student protest -- remained encircled by police armed with sticks who have trapped them outside a monastery compound in the town of Letpadan since Monday. 

The United Nations human rights chief warned Wednesday that widespread abuses of minority rights in Myanmar threatened to undermine reforms in the country.

"Myanmar had promised to end the era of political prisoners, but now seems intent on creating a new generation by jailing people who seek to enjoy the democratic freedoms they have been promised," U.N. High Commissioner for Human Rights Zeid Ra'ad Al Hussein said in a statement.

Dozens of female prisoners were injured in a fierce firefight between rebels and soldiers in northeastern Myanmar following an attack on a government convoy, state media said Tuesday.

The Global New Light of Myanmar said the military launched airstrikes after ethnic Kokang fighters attacked vehicles carrying local people, government workers and inmates from a nearby prison, in the latest assault on civilians trying to escape deadly clashes in Shan state.