The EU sanctioned Myanmar's top junta chief and 10 other officials on Monday after demonstrators took to the streets for fresh anti-coup protests against the military.
Myanmar's junta has unleashed deadly violence on protesters who have risen against the military's ousting of civilian leader Aung San Suu Kyi last month.
The crackdown has drawn international condemnation, and in a fresh bid to step up the pressure, the European Union placed Myanmar junta chief Min Aung Hlaing on an assets freeze and visa ban blacklist Monday.
Min Aung Hlaing is "responsible for undermining democracy and the rule of law in Myanmar", the bloc's official journal said.
The bloc also hit nine other senior military officers and the head of Myanmar's election commission with sanctions in the form of travel bans and asset freezes.
Germany earlier condemned the level of violence in Myanmar as "completely unacceptable".
More than 2,600 people have been arrested and 250 killed since the February 1 coup, according to the Assistance Association for Political Prisoners (AAPP), a local monitoring group that has warned fatalities could be even higher.
One of those held, Aung Thura, a journalist with the BBC's Burmese service, was freed on Monday, the broadcaster said in a news story on its website.
He had been detained by men in plainclothes while reporting outside a court in the capital Naypyidaw on Friday.
A second journalist detained at the same time, Than Htike Aung from the local outlet Mizzima, was still in custody.
The junta has sought to stem the flow of news about the protests and crackdown, revoking the licenses of independent local media -- including Mizzima -- raiding newsrooms and arresting journalists.
Scores of people, including teachers, marched on Monday through the pre-dawn streets of Mandalay, the country's second-largest city, some carrying placards calling for UN intervention in the crisis.
Mandalay has seen some of the worst violence of the crackdown and recorded eight more deaths on Sunday, a medical source told AFP, adding that as many as 50 people were injured.
Machine gunfire rang out late into the night across the city of 1.7 million.
"People were really scared and felt insecure the whole night," a doctor told AFP by phone.
To protest the brutality of the crackdown, a group of doctors in Mandalay staged a "placard only" demonstration by lining up signs in the street, Voice of Myanmar reported.
A group of monks staged a similar "monkless" protest.
There were also early morning protests in parts of Yangon, the commercial capital and largest city, where drivers honked their horns in support of the anti-coup movement.
Residents in Yangon's Hlaing township released hundreds of red helium balloons with posters calling for a UN intervention to stop atrocities, according to local media.
One man was also killed during daytime clashes with security forces in the central city of Monywa Sunday and hundreds turned out to protest a day later, local media reported.
International concern has been growing over the junta's brutal approach as the death toll climbs, with a senior UN expert warning the military is likely committing "crimes against humanity".
But so far the generals have shown little sign of heeding calls for restraint as they struggle to quell the unrest.
As EU foreign ministers gathered in Brussels to sign off on the sanctions, Germany's Heiko Maas said the violence must stop.
"The number of murders has reached an unbearable level, and that is why we will not be able to avoid imposing sanctions," he told reporters.
The United States and Britain have already taken similar steps.
Myanmar's regional neighbours have also weighed in, with Indonesia and Malaysia calling for an emergency summit of the 10-country Association of Southeast Asian Nations to discuss the crisis.
Following the call, Singapore's Foreign Minister Vivian Balakrishnan embarked on a whistle-stop diplomatic tour including meetings in Brunei, Malaysia and Indonesia.
On the commercial front, French energy giant EDF announced that a $1.5-billion hydropower dam project in Myanmar had been suspended in response to the coup.
Australia and Canada have meanwhile confirmed they are providing consular assistance to two business consultants detained in Myanmar.
It is understood that Matthew O'Kane and Christa Avery, a dual Canadian-Australian citizen, are under house arrest after trying to leave the country on a relief flight Friday.
The couple runs a consultancy business in Yangon.
The Canadian and Australian foreign ministries have refused to comment further on the case.