The Turkish government is blocking access for independent investigations into alleged mass abuses against civilians across southeast Turkey, Human Rights Watch said on Monday.

The alleged abuses include unlawful killings of civilians, mass forced civilian displacement, and widespread unlawful destruction of private property. The government should promptly grant the United Nations Office of the High Commissioner for Human Rights permission to enter the area and investigate according to its standards.

“The Turkish government’s effective blockade of areas of the southeast fuels concerns of a major cover-up,” said Emma Sinclair-Webb, senior Turkey researcher at Human Rights Watch. “The Turkish government should give the UN and nongovernmental groups immediate access to the area to document what’s going on there.”

At least 338 civilians have been killed in places where security forces and the Civil Protection Units (YPS), the armed group linked to the PKK, have clashed.