Teachers and students in Myanmar rallied on Friday to a growing civil disobedience campaign as the anti-coup protest movement won the support of ousted leader Aung San Suu Kyi’s party.

Stepping up measures to quell discontent, police arrested one of Suu Kyi’s veteran aides and dozens of people who had joined noisy demonstrations against Monday's coup.

International pressure on the junta increased with the UN Security Council urging the release of detainees and Washington considering sanctions on the ruling generals.

Teachers became the latest group to join a civil disobedience campaign with some lecturers refusing to work or cooperate with authorities over the coup that halted a long and unsteady transition to democracy.

The disobedience campaign, which began with doctors, has also spread to some government offices and on Friday won the formal backing of Suu Kyi’s National League for Democracy party.

In a statement, the party denounced the coup and Suu Kyi’s detention as “unacceptable” and said it would help people who are arrested or sacked for opposing the takeover.

Army chief Min Aung Hlaing took power citing alleged irregularities in a November election that the party won in a landslide.

‘Will of the people’

President Joe Biden said the US was working with allies to address the takeover. “There can be no doubt in a democracy force should never seek to overrule the will of the people or attempt to erase the outcome of a credible election,” he said.