ANKARA (Reuters) - The separatist Kurdistan Workers Party (PKK) denied on Wednesday carrying out a bomb attack which killed six people in Ankara, after Turkish officials said the attack bore the hallmarks of the militant group.
"We have no connection with the attack," the PKK said in a statement posted on the Firat news agency Web site, which has close links to the guerrillas and has published its statements.
The outlawed PKK has been fighting for an ethnic homeland in Turkey since 1984 and Ankara blames it for more than 30,000 deaths. It has carried out suicide bombings in the past.
Ankara's governor said earlier on Wednesday a suicide bomber had carried out the attack in Turkey's capital on Tuesday, and that the type of explosives used pointed to Kurdish separatists.
"It is understood the incident was caused by the explosion of a plastic (explosives) bomb on this person's body and the incident's style matches the methods of the separatist organisation," Kemal Onal told reporters.
Tuesday's explosion, the worst in the capital in at least a decade, comes amid heightened political tension.
Prime Minister Tayyip Erdogan's Islamist-rooted government has called national polls ahead of schedule to resolve a dispute with the secularist elite over a recent presidential election.
The secular establishment, including the military, judges and opposition parties, derailed the government's plan to elect their candidate for president, fearing he might weaken the official separation of religion and state.
The PKK, considered a terrorist organisation by the United States and the European Union, ended a unilateral ceasefire on May 18 and security experts had expected attacks to escalate.
Turkey has repeatedly urged Iraq and the United States to crack down on an estimated 4,000 PKK rebels who use northern Iraq as a springboard to hit targets inside Turkey.
Last month chief of General Staff, General Yasar Buyukanit called for a military operation into northern Iraq to quash them and Erdogan said late on Wednesday he agreed with the army.
"On this issue there can be no question of any difference of opinion with our armed forces, with our soldiers ... On this issue, when it is necessary this step will be taken," he was quoted as saying by state-run news agency Anatolian.
Leading newspapers Hurriyet and Radikal said the blast took place shortly before military commanders, including Buyukanit, were due to pass the area to go to a defence industry reception.
Separately, Adana Governor Ilhan Atis told state-run Anatolian news agency that a would-be suicide bomber had been detained in the southern city while trying to escape in a car. The woman had 11.3 kg (25 lb) of explosive, two hand bombs and a dozen detonators, he added.
NTV news channel said seven people were arrested in Istanbul on suspicion that they were preparing a similar attack in Turkey's biggest city.
Ankara governor Onal said 91 people were wounded in Tuesday's attack.
Kurdish separatists, leftist militants and hardline Islamists have all launched bomb attacks in Turkey in the past.
Turkish media reported earlier that eight people had been detained in connection with the blast. The governor gave no details and police declined to comment.
Turkey's lira currency fell on Wednesday, hit by worries over domestic instability after the blast.
(Additional reporting by Selcuk Gokoluk in Ankara, Emma Ross-Thomas in Istanbul and Seyhmus Cakan in Diyarbakir)