The UN special rapporteur for Myanmar slammed the country’s military for the killing of at least 70 people since protests erupted against its power grab in February, citing growing evidence of crimes against humanity – including murder, persecution and torture.

Talking about “a horrible truth”, human rights investigator Thomas Andrews told the UN Human Rights Council on Thursday that “the country of Myanmar is being controlled by a murderous, illegal regime”.

More than half of those killed were under age 25, Andrews said, adding more than 2,000 people have been unlawfully detained since the coup and violence is steadily increasing.

“There is extensive video evidence of security forces viciously beating protesters, medics, and bystanders. There is video of soldiers and police systematically moving through neighbourhoods, destroying property, looting shops, arbitrarily arresting protesters and passersby, and firing indiscriminately into people’s homes,” he said.

Andrews called for multilateral sanctions to be imposed on senior military leaders and on the country’s major sources of revenue, “including military-owned enterprises and Myanmar’s oil and gas enterprises”, he said.

“It should come as little surprise that there is growing evidence that this same Myanmar military, led by the same senior leadership, is now engaging in crimes against humanity.”

A few hours later, Myanmar rejected the accusations. “Authorities have exercised the utmost restraint to deal with the violent protests,” said in a video message Chan Aye, the permanent secretary of the ministry of foreign affairs.

His written statement – the video was cut short – also said Myanmar was undergoing “extremely complex challenges” and facing a “delicate situation”, and insisted the military leadership did not want to stall a budding democratic transition.

“In this respect, Myanmar would like to seek the understanding from the United Nations and international community on its efforts to maintain sovereignty, political independence, territorial integrity, national unity and social stability throughout the country,” it said.

Myanmar has been in chaos since its military toppled the elected government of Aung San Suu Kyi on February 1. The power grab triggered huge protests nationwide.

The army has justified the coup by saying the election, won by Aung San Suu Kyi’s National League for Democracy party, was marred by fraud – an assertion rejected by the electoral commission.

In the latest round of bloody clashes between security forces and protesters on Thursday at least seven people were killed.

A veteran diplomat, Chan Aye used to serve as the right-hand man of the deposed leader Aung San Suu Kyi, who acted as state councilor before the military seized power.

“There are questions, given that his heart was not in the speech, on whether he was speaking under duress, whether he was in fear of reprisal,” Al Jazeera’s James Bays said, pointing to Chan Aye’s “mumbling” tone.

The diplomat’s statement was in stark contrast to last month’s speech made by then-Myanmar Ambassador to the UN Kyaw Moe Tun who denounced the military coup, urging the international body to use “any means necessary” to halt the generals. He was fired the day after, while his successor resigned soon after taking the role.

‘Need help now’

Last week, the Andrews urged the UN Security Council to impose an arms embargo and targeted sanctions again Myanmar’s military.

The Security Council, which includes Myanmar’s main traditional backer China, has not heeded that call. Andrews insisted the people of Myanmar need “not only words of support but supportive action.”

“They need the help of the international community now,” he said.

Andrews suggested countries should find a way to side-step the perpetually blocked Security Council and impose coordinated sanctions.

“The reluctance of a few nations to act should not prohibit the coordinated action of those that are,” he said.

He called for the creation of an emergency “Coalition for the People of Myanmar” to coordinate sanctions and an arms embargo, and also seek to try Myanmar’s senior security officials under universal jurisdiction.

New charges

Military spokesman Brigadier General Zaw Min Tun told a news conference in the capital, Naypyitaw, on Thursday that Aung San Suu Kyi had accepted illegal payments worth $600,000, as well as gold while in government.

The information had been verified and many people were being questioned, he added.

He alleged President Win Myint and several cabinet ministers also engaged in corruption, and that he pressured the country’s election commission not to act on the military’s reports of irregularities.

Al Jazeera’s Tony Cheng, reporting from Bangkok in neighbouring Thailand, noted Zaw Min Tun failed to provide evidence of the new allegations.

“But we assume that these will be part of new charges which will be used to extend [Aung San Suu Kyi’s] detention,” he said.

Zaw Min Tun also reiterated the military would only be in charge for a certain period before holding an election. “We are on the road to authentic democracy,” he said.

The military government has previously promised a new election within a year, but has not set a date.

•Text (excluding headline): Al Jazeera and News Agencies.

Update news