BRUSSELS, July 28, 2008 (AFP) - The NATO military alliance and leaders in the West and the Middle East Monday condemned the two bombings in Istanbul that killed 17 people as a heinous terrorist attack and pledged support for Turkey.

'I condemn in the strongest terms the bombings that occurred in Istanbul,' NATO chief Jaap de Hoop Scheffer said.

'These appalling terrorist attacks targeted innocent civilians in a deliberate and brutal way,' he said, adding that NATO would stand by its alliance member Turkey 'in the fight against terrorism.'

Declarations of support also came from the European Union and the United States.

EU foreign policy chief Javier Solana pledged the bloc's backing of Ankara in its efforts to bring 'the perpetrators of this heinous terrorist act' swiftly to justice.

In Washington, National Security Council spokesman Gordon Johndroe said the US stands as a partner 'with the people of Turkey as they confront terrorism.'

Turkish Prime Minister Recep Tayyip Erdogan Monday all but named the outlawed Kurdistan Workers' Party (PKK) as responsible for the attacks, describing the explosions as 'the cost' of an intensified military crackdown against the rebels in Turkey and in neighbouring northern Iraq, where they take refuge.

'Unfortunately, the cost of this (military action) is heavy. The incident last night was one such example,' Erdogan said at the scene of the blasts as residents chanted, 'Down with the PKK,' even as a senior Kurdish militant denied that the liberation movement was involved.

The explosions were the deadliest attack against civilians in Turkey since 2003, when 63 people were killed in four suicide bombings in Istanbul blamed on Al-Qaeda.

Strong reaction also came from the Council of Europe, which said the bombs planted in concrete rubbish containers on a street with shops and cafes in the popular Gungoren neighbourhood on Istanbul's European side were a 'callous and calculated act of indiscriminate terrorism against innocent passers-by.'

'Terrorism has no place in a civilised and democratic society, where the ballot box and the debating chamber take precedence over the bomb and the gun,' said the council's secretary general, Terry Davis, in a statement.

Istanbul Governor Muammer Guler put the death toll at 17, five of them children, and warned it could rise with six people in critical condition.

In London, British Foreign Secretary David Miliband said the attacks 'on innocent civilians deserve the condemnation of the international community,' while Sweden's top diplomat, Carl Bildt, said they demonstrate 'once again that terrorism is a threat to our open societies.'

Italian Foreign Minister Franco Frattini not only expressed 'solidarity' with Turkey in the fight against terrorism but again expressed Italy's support for Turkey's candidacy to eventually join the European Union, a position that is not shared by all EU member states including France.

Jordan's Minister of State for Information Nasser Judeh condemned 'this terrorist attack and any other attack that targets innocent people.'

'Jordan's position is clear. It condemns all forms of terrorism regardless of the perpetrators,' he said.

As Erdogan vowed a firm response to the 'savagery,' a Kurdish leader, Zubeyir Aydar, denied any involvement to the pro-PKK Firat news agency.

He said the attack was the work of 'sinister forces' timed to coincide with the anti-secular trial of the ruling AKP party and the pending case against the shadowy 'Ergenekon' nationalist group, which is alleged to have organised attacks and plotted assassinations to create chaos and prompt a military coup against Erdogan's government.