A major security sweep, under way since Tuesday's blast, resulted in the discovery of three remote-control bombs buried in the ground alongside a road outside the main regional city of Diyarbakir, the governor's office said.

The devices, planted in a tin box, a gas canister and a jar, contained C-4 plastic explosives, often used by separatist Kurdish rebels, and were designed to be set off by telephone, the statement said.

Meanwhile, a bomb went off near army lodgings in Baskale, in Van province to the north, shattering windows of nearby buildings, but causing no casulaties, Anatolia news agency reported.

In downtown Diyarbakir, the police used tear gas and water cannons to disperse Kurdish protestors accusing the government of covering up the identities of the perpetrators of the blast, which killed seven children and three adults and wounded 14 others at a crowded park Tuesday evening.

The protests appeared to have been triggered by a claim of responsibility by a shadowy nationalist Turkish group, the Turkish Revenge Brigade, which vowed on its website to avenge the killings of Turks by the separatist Kurdistan Workers' Party (PKK).

The authorities have played down the claim as an attempt for publicity, and even though no official statement has been made about the perpetrators, police have said that suspicion fell on the PKK.

Officials said the bomb went off while it was being carried to another location, apparently accidentally.

Groups of protestors, mostly young men, gathered at different spots across Diyarbakir, chanting slogans praising the PKK and denouncing the government. "The murderers should be found," they chanted, while some shouted "Revenge".

The demonstrators burned tyres, overturned garbage containers and hurled stones at the security forces.

The police detained at least three demonstrators and one person was injured, witnesses said.

The PKK, blacklisted as a terrorist group by Ankara and much of the international community, has a solid base in Diyarbakir.

Interior Minister Abdulkadir Aksu visited the city Thursday, but declined to give details about the probe until it is completed.

He promised that those responsible for the blast would be found and brought to justice "in the shortest possible time".

Kurdish politicians called the blast "a provocation," stressing that it occurred just a day after they appealed to the PKK to call a ceasefire.

The 22-year conflict between the PKK and the army has harmed Kurdish confidence in the state, especially due to serious human rights violations and rogue elements in the security forces acting outside the law.

In a landmark trial in June, two soldiers were sentenced to almost 40 years each for the deadly November bombing of a bookstore owned by a former PKK militant in the town of Semdinli.

The PKK took up arms for Kurdish self-rule in the southeast in 1984. The conflict has claimed more than 37,000 lives.

The group has notably stepped up attacks on the security forces this year after it called off a five-year unilateral ceasefire in June 2004.

Kurdish militants have also claimed 16 bombings across Turkey, including attacks in tourist resorts in the west, which killed a total of 12 people and injured about 200.