The Arakan Rohingya Salvation Army (Arsa) announced a truce on Sunday, urging Myanmar's army to lay down weapons as well, BBC reports.
However, the government spokesman Zaw Htay said Myanmar would not negotiate with "terrorists" and its military is fighting against them.
Arsa announced the ceasefire on Twitter, saying it was "in order to enable humanitarian actors to assess and respond to the humanitarian crisis" in Rakhine.