A six-year-old boy became the fourth child to die from the attack when he succumbed to injuries in hospital on Sunday, the agency said.

The boy was the son of a local community leader in Ulalar in the eastern province of Erzincan. The timed bomb exploded in his father's garage on Saturday, Anatolia said.

Three other boys aged between six and 12, who were playing near where the bomb exploded, died on Saturday.

While local governor Ali Gungor blamed the attack on Kurdish "terrorists," no group has yet claimed responsibility for the bomb.

Turkey has seen an escalation of attacks by the Kurdish Workers' Party (PKK), a separatist group classed as a terrorist organisation by Turkey, the European Union and the United States.

The Kurdish conflict in Turkey has claimed some 37,000 lives since the PKK began 1984 when the PKK began an armed campaign for an independent Kurdish homeland in the southeast of the country.

The PKK has stepped up its attacks since a 1999 ceasefire broke down in 2004.