The United States on Monday imposed sanctions on two military leaders of Myanmar’s junta and warned of further action in response to the February 1 coup in the South Asian country, Reuters reported. America had sanctioned 10 other leaders earlier this month.

The sanctions were announced against General Maung Maung Kyaw, who is the air force commander in chief, and Lieutenant General Moe Myint Tun, a former army chief of staff and commander of one of the military’s special operations bureaus which oversee operations from Myanmar’s capital, Naypyidaw.

The Treasury Department’s Office of Foreign Assets Control said the action was “in response to the security forces’ killing of peaceful protesters” after two people were killed over the weekend during a demonstration to demand the restoration of democracy, according to Al Jazeera. A 23-year-old woman also died from her injuries after being shot in the head on February 9.

“The military must reverse its actions and urgently restore the democratically elected government in Burma, or the Treasury Department will not hesitate to take further action,” the US department said.

On February 11, the US had sanctioned 10 generals, including Senior General Min Aung Hlaing, who led the coup. The latest round of sanctions freeze any assets that Moe Myint Tun and Maung Maung Kyaw might have in the US and bar American companies and individuals from doing business with them.

“We will not hesitate to take further action against those who perpetrate violence and suppress the will of the people,” US Secretary of State Antony Blinken said on Monday. “We call on the military and police to cease all attacks on peaceful protesters, immediately release all those unjustly detained, stop attacks on and intimidation of journalists and activists, and restore the democratically elected government.”

The coup has triggered days of protests across Myanmar and a campaign of civil disobedience, in which doctors, teachers, engineers and other civil servants have stopped work.

The authorities have responded by launching a crackdown on the demonstrations. The Assistance Association for Political Prisoners, which has been tracking detentions since the coup, said 684 people have been arrested, charged or sentenced since the military seized control of the country. Some 637 remain in custody, according to Al Jazeera.