The two men, who were apprehended in an operation on Wednesday in Istanbul's Esenyurt suburb on Wednesday, had sought to evade capture by hurling a hand grenade at the security forces, the Anatolia news agency reported.

The suspects, believed to belong to the separatist Kurdistan Workers' Party (PKK), had been trained for sabotage acts and sent to Istanbul to carry out "sensational attacks," the anti-terror department of the Istanbul police said.

The security forces also seized a hand grenade, two automatic rifles, 14 pistols, a fake ID card and documents with "organizational content" in the suspects' lodgings.

Police said investigations pointed to the two men being responsible for bomb blasts outside a government building in Istanbul and at the Esenyurt office of the ruling Justice and Development Party, on August 27 and April 5.

Eight people were wounded in the blasts which were claimed by a shadowy Kurdish group, the Kurdistan Freedom Falcons (TAK). Officials say the group is a PKK front.

TAK and PKK have claimed 16 bomb blasts across Turkey this year, in which a total of 12 people were killed and about 200 others injured.

The Kurdish conflict in Turkey has claimed more than 37,000 lives since 1984 when the PKK, blacklisted as a terrorist group by Ankara and much of the international community, took up arms for self-rule in the mainly Kurdish southeast.