Speaking before the Human Rights Council in Geneva, the UN's deputy rights chief Nada al-Nashif expressed concern after Washington announced sanctions on the generals behind last week's coup in Myanmar.

Other countries are considering similar moves.

"Any sanctions under consideration should be carefully targeted against specific individuals who are credibly alleged to have violated the people's rights," al-Nashif said.

"Leaders of this coup are an appropriate focus of such actions," she said, adding that "it is of critical importance that no harm should be inflicted on the most vulnerable people in the country."

She was addressing a special session of the council urgently called for by Britain and the European Union to address the situation in Myanmar after the military there seized control on February 1.

The new US sanctions target Min Aung Hlaing and other top generals, after President Joe Biden announced his administration was cutting off the military's access to $1 billion in funds.

- 'World is watching' -

Huge crowds have for days thronged cities around Myanmar to demand the return of ousted leader Aung San Suu Kyi, and there has been concern over harsh police tactics in dispersing the largely peaceful crowds.

"The world is watching," al-Nashif warned.

"Draconian orders have been issued this week to prevent peaceful assembly and free expression, and police and military presence on the streets has grown progressively over the last several days.

"Let us be clear: the indiscriminate use of lethal or less-than-lethal weapons against peaceful protestors is unacceptable," she said.

During Friday's one-day session, diplomats will consider a draft resolution demanding the immediate release of Suu Kyi, who until the coup on February 1 was the country's de facto civilian leader.

She was detained with dozens of other members of her National League for Democracy party, including President Win Myint, ending a decade of civilian rule and triggering international condemnation.

The resolution text also demanded "the restoration of the democratically-elected government," and the "immediate and permanent lifting of restrictions on the internet, telecommunication and social media".

And it urged "full and unrestricted access" to the country by UN rights observers.

The draft meanwhile stopped short of calling for sanctions against the generals behind the coup.

Observers suggested stronger positions may have been avoided in the text to obtain broader support in the council, where consensus backing is preferred.