A convoy carrying the lawmakers to Dortyol, in the Mediterranean province of Hatay, was stopped near a neighbouring town on the orders of the local governor, the report said.

Security forces blocked the road after the governor said the members of the Peace and Democracy Party (BDP), Turkey's main Kurdish party, would not be allowed into Dortyol.

He cited the risk of "developments that would seriously upset public order."

Ethnic tensions erupted in Dortyol after suspected Kurdish rebels peppered a police van with bullets late Sunday, killing four officers, in the latest stage of a dramatic escalation in separatist violence this year.

The attack sparked street scuffles between the town's Turkish and Kurdish communities, prompting the deployment of riot police reinforcements.

Kurds fanned tensions by chanting support for the outlawed Kurdistan Workers' Party (PKK), which has led a bloody 26-year insurgency against Ankara.

Turks meanwhile vandalised Kurdish-owned shops and set fire to the local BDP office.

Dortyol remained tense Thursday as a group of some 1,000 Kurds assembled to protest the ban on the BDP visit, NTV television said.

The channel aired footage showing riot police, some wielding automatic rifles, on guard at the edge of the town's mainly Kurdish neighbourhood.

Led by party chairman Selahattin Demirtas, the BDP delegation had planned to visit Dortyol to show solidarity with its Kurdish residents who, it claimed, were not given proper protection by the authorities, and to appeal for peace.

"The members of a party represented in parliament are not allowed into town on the pretext of ensuring calm and security," BDP lawmaker Ayla Akat said before the convoy drove back, Anatolia reported.

"One cannot achieve calm and security like that," he added.

The PKK has significantly stepped up attacks since its jailed leader Abdullah Ocalan said in May he was abandoning efforts to seek dialogue with Ankara.

Many Turks are also outraged at government pledges to boost Kurdish freedoms despite the violence.

The PKK, listed as a terrorist group by Turkey and much of the international community, took up arms for self-rule in the Kurdish-majority southeast in 1984, sparking a conflict that has claimed some 45,000 lives.