SITTWE, Myanmar — Violence between the Rohingya, a persecuted Muslim population, and Myanmar’s security forces escalated over the weekend as two soldiers were killed by crudely armed attackers, said government officials and Muslim residents. In retaliation, troops of the Buddhist-majority government used helicopters to fire at the attackers in dense forest in northwestern Myanmar, a government spokesman said.

The two soldiers were killed Saturday by attackers armed with guns, knives and spears near the village of Gwason, south of Maungdaw, the main town in northern Rakhine, said the state information officer, U San Nwe. About 500 attackers were involved in the clash, he said. The area is closed to Western journalists, making it impossible to verify the scale of the fighting.

The remote enclave of northern Rakhine State, close to the Bangladeshi border, has been under siege since the government sent security forces to hunt for what it said were armed Rohingya assailants who had killed nine police officers in early October.

Since then, human rights groups have received reports of killings of unarmed Rohingya men by Myanmar soldiers, rapes of Rohingya women by soldiers in a number of villages, and beatings of Rohingya men held in detention in the town of Maungdaw. Before the latest attack, as many as 100 Rohingya civilians may have been killed, the groups say.