Myanmar’s military has assured the United Nations that it will take “harsh” action against soldiers who engaged in sexual violence against Rohingya Muslims in the Rakhine state, state-run Myanmar News Agency reported on Tuesday. A delegation of the UN Security Council was in the country on Monday.

The military is “taking harsh and stronger actions against such offenders”, military Commander-in-Chief Min Aung Hlaing told the envoys. However, in a Facebook post after meeting the envoys, he claimed that “no sexual violence happened in the history” of the military.

Many Rohingya Muslim refugees who fled to Bangladesh have described incidents of rape by the military back home.

The delegation also met de facto leader and State Counsellor Aung San Suu Kyi on Monday. She has pledged to investigate any credible accusations of abuse, the diplomats told Reuters. She reportedly told them of Myanmar’s difficulties in transitioning to rule of law after decades of military dictatorship.

Suu Kyi also urged them to understand the complex nature of the conflict in Rakhine state and said Myanmar would bring the refugees back, AFP reported.

The delegation began its four-day visit to the region on Saturday. It visited Bangladesh to observe firsthand the condition of the refugees, and also met Prime Minister Sheikh Hasina before leaving for Myanmar on Monday.

Lakhs of Rohingya Muslims have fled from Rakhine to neighbouring Bangladesh since August 2017, after security forces began a violent crackdown against the community. The United Nations and the United States have called it “ethnic cleansing”, and Aung San Suu Kyi has faced widespread criticism for not doing enough to stop the persecution.