BANGKOK — Two journalists arrested last week in Myanmar had obtained photographs from residents of a village in which, the country’s army chief has said, a mass grave was found. The area is in northern Rakhine State, where a military campaign against Rohingya Muslims has raged for more than three months.

The Reuters reporters U Wa Lone and U Kyaw Soe Oo were arrested on Dec. 12 after meeting with police officers in Yangon, the country’s commercial capital.

At the time, Myanmar’s Ministry of Information said the journalists had tried to illegally procure information about Rakhine State, where international human-rights monitors say Myanmar’s military has killed and raped thousands of Rohingya. Ethnic Rakhine Buddhists, who compose the state’s ethnic majority, have also been accused of participating in the bloodletting and burning of Rohingya villages.

Three days after the reporters were arrested, five ethnic Rakhine residents of the village of Inn Din, in northern Rakhine, were detained, including the principal of the local school and three teachers.