An advocacy group said security forces killed 12 protesters in one of the deadliest days since the military took power in Myanmar, while the junta added new bribery allegations to its charges against deposed leader Aung San Suu Kyi.

The bloodshed came hours after the UN Security Council had called for restraint from the army, which has been trying to put down daily anti-coup protests and paralysing strikes since it took power on Feb 1.