The group calling itself the Turkish Revenge Brigade (TIT) said on a website that it had carried out the attack in retaliation for mounting violence by separatist Kurdish rebels.

"We vow... to kill 10 Kurds for every Turk the PKK (Kurdistan Workers' Party) kills in the west" of Turkey, said a statement.

The website also featured photographs of what looked like a bomb, attached to a gas canister and a walkie-talkie, being placed inside a plastic bucket.

The group said the photographs were taken before Tuesday's bombing in Diyarbakir, the main city in Turkey's Kurdish-populated southeast, which killed 10 people and injured 14 others.

However, sources close to the police dismissed the claim as a bid for publicity by a little-known group.

"They are only trying to spread their own propaganda and make their names heard," a source told AFP on condition of anonymity.

Local officials suspect the PKK, which has been fighting the government since 1984 in a drive for Kurdish self-rule in the southeast, to be behind the attack in Diyarbakir.

The TIT first came to public attention in 1998 when its militants seriously wounded the then-chairman of Turkey's main human rights group in his office in downtown Ankara.