Turkish President Recep Tayyip Erdogan said Monday his country was suffering "one of the biggest waves of terrorism in its history", vowing to crush the Islamic State (IS) jihadists and Kurdish rebels behind a string of attacks.

"We will hit these terrorist organisations as hard as possible," Erdogan said in a speech in Istanbul, two days after a suspected IS suicide attack in Istanbul that killed four foreigners.

"Faced with the terrorists' new strategies we will develop new modes of combat and quickly overcome them," Erdogan said, promising democratic values would not be sacrificed in the fight.

Of the six bombings that have rocked Turkey in the past eight months, killing over 200 people, four have been blamed on IS, with Kurdish rebels claiming the other two.

Turkey's strongman leader focused his attacks on the outlawed Kurdistan Workers Party (PKK), which resumed its three-decade-long insurgency against the state last summer following the collapse of a shaky two-year truce.

He also took aim at his European counterparts, whom he has repeatedly accused of taking an indulgent approach towards PKK sympathisers.

Referring to the tent set up outside EU buildings by pro-PKK activists in Brussels during last week's EU-Turkey summit on migration, he demanded: "How can the EU, which considers this (PKK) a terrorist organisation, tolerate such a situation?

"Where's the sincerity," he demanded to know, accusing the EU of "hypocrisy".

On Sunday, Turkey summoned Belgium's ambassador to Ankara to protest over the tent.
Source: AFP