Myanmar's security forces have killed more than 300 people in an attempt to crush opposition to the February 1 coup, with nearly 90% of the victims shot dead and a quarter of them shot to the head. , according to data from an advocacy group and local media.

A spokesman for the board said 164 protesters and nine members of the security forces had died as of Tuesday. Reuters was unable to independently verify all accounts.

More than 300 people killed since the coup in Myanmar

The killings have sparked outrage and prompted some sanctions from Western countries, including the United States. The use of deadly force against civilians has also been condemned by some Southeast Asian neighbors, who tend to be moderate in their criticism.

"Crimes against humanity are committed on a daily basis," said the nonprofit Association for Assistance to Political Prisoners (AAPP), which has been recording the deaths, as well as nearly 3,000 people detained, charged or convicted since the coup.

The group had recorded 320 deaths as of March 25.

Their data shows that at least 25 percent of those who died were shot to the head, raising suspicions that they were deliberately targeted for killing. Complete data are not available for all deaths.

"Everything indicates that the troops are adopting shoot-to-kill tactics to suppress the protests," Amnesty International said earlier this month.

The board denies the excessive use of force and says its actions have complied with international standards in the face of a situation that it says is a threat to national security.

Almost 90% of the dead were men. About 36% were 24 years old or younger.

The youngest victim, seven-year-old Khin Myo Chit, was shot and killed in the second city of Mandalay on Tuesday. She was in her house with her father when she was killed.

Win Kyi, 78, is the oldest person on record to be killed and was among 50 people killed in Yangon's Hlaing Thayar district on March 14, the bloodiest day yet.