A European official has voiced concern over Turkish security forces' fight against Kurdish rebels, saying the respect for human rights has "deteriorated at an alarming speed."

Ending a nine-day visit to Turkey on Thursday, Nils Muiznieks the Council of Europe's human rights commissioner, also criticized reduced freedom of the media and of speech as well as the erosion of the judiciary's independence.

Muiznieks acknowledged Turkey's right to fight terrorism, but questioned the around-the-clock curfews imposed during large-scale operations against Kurdish militants in urban areas, which have displaced tens of thousands and caused civilian deaths.

Muiznieks also criticized "low government tolerance toward criticism and alternative views," citing among other things the more than 1,800 cases launched against people accused of insulting the president and the thousands websites that have been blocked.