Myanmar security forces on Wednesday raided a compound of striking railway workers opposed to the military junta.
The railway staff in the country's main city Yangon are part of a civil disobedience movement that has crippled government businesses with strikes on banks, factories and shops.
The movement began last month after Myanmar’s military ousted Aung San Suu Kyi’s democratically-elected government in a coup.
In Myanmar's second biggest city, Mandalay, protesters staged a sit-in protest on Wednesday, chanting, "The revolution must prevail."
Security forces have cracked down with increasing force on daily, nationwide protests, leaving the Southeast Asian nation in turmoil.
More than 60 demonstrators have been killed and 1,900 people have been arrested since the coup, according to a political prisoner advocacy group.
On Tuesday, Zaw Myat Linn, an official from Suu Kyi's National League for Democracy, died in custody after he was arrested.
He was the second party figure to die in detention in two days.
CCTV footage showed the moment security forces in Myanmar took another NLD party member and former volunteer guard of Aung San Suu Kyi, Ja Mar, into custody.
Video showed a group of soldiers taking him from his home in the city of Bago Tuesday night and shoving him into a vehicle.
Police that day also cracked down on independent media, raiding two news outlets and detaining two journalists.
Meanwhile, the UN failed to officially condemn the coup, but international powers have called for restraint by the military.
U.S. State Department spokesman Ned Price said this week they are “repulsed” by the army’s use of lethal force against protesters.
The junta has brushed off condemnation of its actions.