Demonstrators at a university in the biggest city, Yangon, chanted support for jailed leader Aung San Suu Kyi and wore red ribbons, her party’s colour.

Ms Suu Kyi and other leaders have been held since the military’s coup.

Earlier, the military detained another senior leader from her National League for Democracy (NLD) party.

Although Ms Suu Kyi has not been seen in public since Monday she is believed to be under house arrest, the NLD said, quoted by the Associated Press news agency.

Myanmar has remained mostly calm in the aftermath of the coup, which has plunged the South East Asian country into uncertainty.

On Friday afternoon, hundreds of teachers and students gathered outside Dagon University, where they displayed the three-finger salute – a sign that has been adopted by protesters in the region to show their opposition to authoritarian rule.

“We will not let our generation suffer under this kind of military dictatorship,” Min Sithu, a student, told the AFP news agency.

Students at Dagon University chanted “Long live Mother Suu” and carried red flags, the colour of the NLD party, AFP reports.

There have been a number of demonstrations in different parts of Myanmar.

Residents in some cities including Yangon have conducted nightly protests from their homes, where they have been banging pots and pans and singing revolutionary songs, and there have also been daytime flash mobs.

Some healthcare workers, teachers and civil servants have either organised small protests or gone on strike, while others have continued to work wearing symbols of defiance such as a red ribbon.

In a pre-dawn phone call with BBC Burmese, Win Htein said he was being taken to the capital, Naypyidaw, by members of the police and the military.

He said he was being detained under sedition laws – which carry a maximum punishment of life imprisonment – although he was not told the exact charge.

“They don’t like what I’ve been talking about. They are afraid of what I’m saying,” he said.

The 79-year-old patron of the NLD and strong supporter of Ms Suu Kyi has given several interviews since the coup criticising the military and its leader Min Aung Hlaing.

A small street protest took place in front of a university in Myanmar’s second city, Mandalay, on Thursday, with reports of four arrests.

Since the ban began on Thursday, many Burmese citizens have appeared to have flocked to other social media platforms like Twitter and Instagram.

Twitter declined comment when asked by the BBC if it had seen a spike in new users or tweets from Myanmar.

The military overthrew Ms Suu Kyi’s government after it claimed a November election won by the NLD was fraudulent, though the country’s election commission said there was no evidence to back up these allegations.

The move has been met with global outrage.

On Thursday, US President Joe Biden called on the military to “relinquish power” and release detained officials and activists. The US had already threatened severe sanctions on Myanmar, which is also known as Burma.

However, the military is seemingly undeterred by the disapproval, continuing down its path of consolidating power and appointing new ministers in the capital Naypyitaw, said the BBC’s South East Asia correspondent Jonathan Head.

The UN Security Council also called on the military authorities in Myanmar to release Ms Suu Kyi and other detained leaders – but stopped short of condemning the coup.

In doing so, it has brought China and Russia behind a call for her release, in what our correspondent has described as a rare show of international unity.

Myanmar is a country of 54 million people in South East Asia which shares borders with Bangladesh, India, China, Thailand and Laos.

It was ruled by an oppressive military government from 1962 to 2011, leading to international condemnation and sanctions.

Aung San Suu Kyi spent years campaigning for democratic reforms. A gradual liberalisation began in 2010, though the military still retained considerable influence.

A government led by Ms Suu Kyi came to power after free elections in 2015. But a deadly military crackdown two years later on Rohingya Muslims sent hundreds of thousands fleeing to Bangladesh and triggered a rift between Ms Suu Kyi and the international community.

She has remained popular at home and her party won again by a landslide in the November 2020 election. But the military have now stepped in to take control once more.