UN Secretary-General Antonio Guterres spoke out against the "use of deadly violence in Myanmar," in a tweet early on Sunday.

He commented after security forces in Myanmar fired live rounds, tear gas and rubber bullets at anti-coup protesters in the country's second-largest city, Mandalay. 

At least two people were killed, emergency workers said.

The country has seen over two weeks of protests after the military ousted civilian leader Aung San Suu Kyi on February 1.  

"The use of lethal force, intimidation and harassment against peaceful demonstrators is unacceptable. Everyone has a right to peaceful assembly," the UN chief said.

"I call on all parties to respect election results and return to civilian rule," Guterres added.

What happened in Myanmar on Saturday

More than 1,000 people joined Saturday's protest in Mandalay.

They marched to commemorate a 20-year-old woman who died after being shot by police at a demonstration on February 9 in Myanmar's capital, Naypyidaw.

About 30 others were injured in the violence near a shipyard, Hlaing Min Oo, the head of a Mandalay-based volunteer emergency rescue team said. Around half of them were shot with live rounds.

The protesters in Mandalay and Myanmar's largest city, Yangon, carried flowers and banners with photos of Mya Thwet Thwet Khine, who was confirmed dead on Friday after spending a week on life support in a hospital. 

Some other protesters on Saturday held signs that read "CDM," in reference to the civil disobedience movement which workers in several industries have recently joined. 

Police crack down on protests

Security forces around Myanmar have used tear gas, water cannon and rubber bullets to disperse protesters since the anti-coup rallies began earlier this month. 

According to The Assistance Association for Political Prisoners, an independent monitoring group, authorities have arrested at least 546 people since the coup. 

More countries condemn violence

The European Union's foreign affairs chief, Josep Borrell, condemned the latest violence against protesters, adding that Brussels will address the events "to take appropriate decisions." 

The US is said it is "deeply concerned" by reports that Myanmar security forces have fired on protesters, US State Department spokesman Ned Price said in tweet on Saturday.

"We stand with the people of Burma," Price added. Myanmar is also known as Burma.

"The violence committed in Mandalay today is unacceptable," the French government said in a statement.

UK Foreign Minister Dominic Raab also condemned the shooting of peaceful protesters and said the UK is considering further action. 

"The shooting of peaceful protesters is beyond the pale," Raab tweeted, adding "we will consider further action, with our international partners, against those crushing democracy and choking dissent." 

The United States, Canada and Britain have recently announced sanctions on military generals.

The opposition in Myanmar called on international institutions to impose sanctions on the junta leaders. The bloc is set to discuss the situation on February 22.

fb,wd,kmm/sri (AFP, Reuters)

This is an updated version of an earlier article.