Myanmar has been convulsed by demonstrations against a coup that ousted civilian leader Aung San Suu Kyi last month, with the junta ordering a brutal crackdown in response.

More than 2,600 people have been arrested and 250 killed, according to the Assistance Association for Political Prisoners, a local monitoring group which warns fatalities could be even higher.

Scores of people including teachers marched through the streets of Mandalay, some carrying placards calling for UN intervention in the crisis.

There were also early morning protests in parts of Yangon, the commercial capital.

Mandalay, the country's cultural hub, 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 had been injured.

Monks held an evening candlelight ceremony, while in one neighbourhood persistent gunfire was reported until about 11:00pm local time (1630 GMT).

One man was also killed during daytime clashes with security forces in the central city of Monywa Sunday.

The Australian and Canadian governments have 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 run a consultancy business in Yangon.

The Canadian and Australian foreign ministries have refused to comment further on the case.

International condemnation by Washington, Brussels and the United Nations has so far failed to halt the bloodshed.

In a new bid to step up diplomatic pressure on the generals, European Union foreign ministers are expected to approve sanctions against 11 junta officials on Monday.