A Myanmar human rights group says more than 600 people have been killed in the military crackdown since the coup on February 1. The military has arrested celebrities, accusing them of inciting protests.
Demonstrators continued to take to the streets on Thursday across the country, including in the largest city of Yangon and the southern city of Dawei.
The rights group, the Assistance Association for Political Prisoners, says more than 20 people were killed on Wednesday alone, and that the death toll stood at 614 as of Thursday.
The military announced on state-run TV on Thursday that it had arrested Paing Takhon, a popular model with fans in Myanmar and Thailand.
Paing Takhon has spoken out against the coup and posted photos on social media of himself demonstrating.
Local media quoted his family as saying soldiers and police took him from his home at around 5:00 a.m. on Thursday.
Also on Thursday, the US Treasury Department announced sanctions on a Myanmar state-owned gem company to cut off the military's sources of funding.
The measures freeze the firm's assets in the United States and ban Americans from doing business with it.
US Secretary of State Antony Blinken said in a statement that the sanctions are a clear signal that Washington will keep increasing pressure on the military's revenue streams until it ceases its violence and releases all those unjustly detained.
The move is the latest in a series of sanctions Washington has imposed on Myanmar military leaders, including Senior General Min Aung Hlaing, as well as companies linked to the military.