The United Nations human rights investigator for Myanmar on Friday urged the UN Security Council to consider imposing punitive sanctions, arms embargoes and travel bans in response to a military coup.
The United States, which imposed its own sanctions on Thursday, urged other UN member states to follow suit, in its first remarks to the Human Rights Council since returning to the forum this week.
Special Rapporteur Thomas Andrews said there were "growing reports and photographic evidence" that Myanmar security forces had used live ammunition against protesters since seizing power almost two weeks ago.
"Security Council resolutions dealing with similar situations have mandated sanctions, arms embargoes, and travel bans, and calling for judicial action at the International Criminal Court or ad hoc tribunals," he told the Council. "All of these options should be on the table."
The 47-member forum was meeting at the request of Britain and the European Union to consider a resolution calling for the release of ousted Myanmar leader Aung San Suu Kyi, and for Andrews and other UN monitors to be allowed to visit.
US Chargé d'Affaires Mark Cassayre said: "We ask all Council members to join the United States and others to ... join us in promoting accountability for those responsible for the coup, including through targeted sanctions."
But China and Russia - which have close ties to Myanmar's military - said they opposed holding the session at all.
"What happened in Myanmar is essentially Myanmar's internal affairs," said Chen Xu, China's ambassador. "China is in contact and communication with relevant parties in Myanmar to promote the relaxation and the return to normal of the situation."
Russian ambassador Gennady Gatilov said human rights issues should be addressed through "open dialogue and cooperation".
"Today's special session is clearly not conducive to that. Attempts to whip up hype around the situation in Myanmar need to cease," he said.
Supporters of Suu Kyi clashed with police on Friday as hundreds of thousands joined nationwide pro-democracy demonstrations in defiance of the junta's call to halt mass gatherings.
More than 350 political and state officials, activists and civil society members, including journalists, monks and students have been taken into custody, said Nada al-Nashif, deputy UN High Commissioner for Human Rights.
Myanmar ambassador Myint Thu said Myanmar would continue to cooperate with the United Nations and uphold international human rights treaties, adding: "We do not want to stall the nascent democratic transition in the country."