Junta chief General Min Aung Hlaing made a televised speech on Monday evening to justify seizing power, while a military statement made clear action would soon be taken against the protesters.

The military banned gatherings of more than five people in parts of Yangon, the nation's commercial capital, and other areas across the country where major rallies had erupted over the weekend and on Monday.

Those rallies had seen hundreds of thousands of people take to the streets.

On Tuesday morning, fresh protests emerged in various parts of Yangon, including near the headquarters of the National League for Democracy (NLD), the party of deposed leader Aung San Suu Kyi, who the military detained on day one of the coup.

The protesters carried anti-coup placards including "We want our leader", in reference to Suu Kyi, and "No dictatorship".

In San Chaung township -- where large gatherings were specifically banned -- scores of teachers marched on the main road, waving a defiant three-finger salute that has become the trademark sign of the protesters.

"We are not worried about their warning. That's why we came out today. We cannot accept their excuse of vote fraud. We do not want any military dictatorship," teacher Thein Win Soe told AFP.

- Military promises -

In his televised address, his first since the coup, Min Aung Hlaing insisted the seizure of power was justified because of "voter fraud".

The NLD won last November's national elections by a landslide but the military never accepted the legitimacy of the vote.

Shortly after the coup, the military announced a one-year state of emergency and promised to then hold fresh elections.

Min Aung Hlaing on Monday insisted the military would abide by its promises. He also declared that things would be "different" from the army's previous 49-year reign, which ended in 2011.

"After the tasks of the emergency period are completed, free and fair multi-party general elections will be held according to the constitution," he said.

"The winning party will be transferred state duty according to democratic standards."

But those pledges were accompanied by threats.

In the face of the increasingly bold wave of defiance, the military released a statement on state TV on Monday warning that opposition to the junta was unlawful.

"Action must be taken according to the law with effective steps against offences which disturb, prevent and destroy the state's stability, public safety and the rule of law," said a statement read by an announcer on MRTV.

- Global outrage -

The United States has led global calls for the generals to relinquish power, and issued a fresh statement on Monday following the junta's warnings against the protesters.

"We stand with the people of Burma and support their right to assemble peacefully, including to protest peacefully in support of the democratically elected government," US State Department spokesman Ned Price said Monday, using Myanmar's former name.

Price also said US requests to speak to Suu Kyi were denied.

Pope Francis on Monday called for the prompt release of imprisoned political leaders.

"The path to democracy undertaken in recent years was brusquely interrupted by last week's coup d'etat," he told a gathering of diplomats.

"This has led to the imprisonment of different political leaders, who I hope will be promptly released as a sign of encouragement for a sincere dialogue."

The UN Human Rights Council said it would hold a relatively rare special session on Friday to discuss the crisis.