The U.N. human rights chief is calling on Turkish authorities to investigate the alleged shooting of unarmed people in southeastern Turkey that turned up in "extremely shocking" footage posted online last week.

Zeid Raad al-Hussein on Monday also voiced concern over reports that the cameraman, Refik Tekin, faces arrest when he leaves the hospital where he is treated for gunshot wounds.

The video purportedly shows people in the mostly-Kurdish town of Cizre wheeling a dead body on a handcart while waving white flags, before apparently being targeted by gunfire.

Turkey has been imposing curfews in Cizre and other towns in the southeast to flush militants linked to Kurdish rebels from urban areas, since the collapse of a peace process.

A human rights group says at least 198 civilians have died.