"Our security forces have displayed an attitude of tolerance unseen in other countries, at the risk of being wounded or killed," Erdogan told reporters.

"No one can level such accusations against them and we will not bother to answer them each and every time."

He was commenting on reports that a group of European Parliament members, in a letter to Erdogan, condemned the authorities' response to the unrest and threatened that Ankara's membership talks with the European Union might be suspended if it fails to guarantee the rights of its Kurdish minority.

"Most recently, five soldiers and a policeman were killed. Those who write such letters should first come and experience what they (the security forces) have been going through," Erdogan said.

The six members of the security forces were killed Wednesday in attacks by the Kurdistan Workers' Party (PKK), an armed separatist group considered as terrorist by Ankara, the EU and the United States, which has been accused of orchestrating the riots.

The violence, which broke out on March 28 in Diyarbakir, the central city of the southeast, saw hundreds of angry Kurdish youths torch banks and public buildings, vandalize shops and attack the police with firebombs.

Twelve people were killed in the region as the security forces opened fire to disperse the crowds, while three women were killed in Istanbul when rioters set ablaze a city bus with a Molotov cocktail.

Another person was killed in a bomb attack on a bus station in Istanbul, claimed by a radical Kurdish group, which also took the blame for Wednesday's bombing of an office of Erdogan's party in the city.