Thousands of anti-coup protesters marched in towns and cities across Myanmar on Monday, witnesses said, demonstrating for a third straight day against the military's removal and detention of elected leader Aung San Suu Kyi a week ago.

Calls to join protests and to back a campaign of civil disobedience have grown louder and more organised since last Monday's coup, which drew widespread international condemnation.

In the biggest city of Yangon, a group of saffron-robed monks marched in the vanguard of Monday's protest with workers and students. They flew multicoloured Buddhist flags alongside red banners in the colour of Suu Kyi's National league for Democracy (NLD), witnesses said.