Myanmar is to investigate whether police have committed abuses against Rohingya Muslims, the government has said, after officials promised that allegations of atrocities against members of the Muslim minority would be looked into.The U.N. human rights office said in a report this month Myanmar's security forces had committed mass killings and gang rapes of Rohingya Muslims and burned their villages since October in a campaign that "very likely" amounted to crimes against humanity and possibly ethnic cleansing.Myanmar has denied almost all allegations of human rights abuses in northern Rakhine State, where many Rohingya live, and says a lawful counterinsurgency campaign has been under way since nine policemen were killed in attacks on security posts near the Bangladesh border on Oct. 9. The military said last week it was setting up a team to investigate alleged atrocities by the security forces and the interior ministry followed that up on the weekend with a promise to investigate police. The Home Ministry said in a statement a "departmental inquiry" would be conducted "to find out whether the police forces have committed illegal actions including violations of human rights during their area clearance operations". The ministry, which is controlled by the military, said action would be taken against personnel "who failed to follow instructions".It is rare in Myanmar for security forces to be held accountable for abuses, or for such allegations to be investigated transparently, rights groups say.Almost 69,000 Rohingyas have fled from Myanmar to Bangladesh since the security force sweep was launched in October, according to U.N. estimates.