AMMAN, Sept 27 (Reuters) - The al Qaeda-linked Nusra Front on Saturday denounced U.S.-led air strikes on Syria, saying they amounted to a war against Islam and vowing to retaliate against Western and Arab countries that took part.

"We are in a long war. This war will not end in months nor years, this war could last for decades," the group's spokesman Abu Firas al-Suri said.

"It's not a war against Nusra Front, it's a war against Islam," he added in an audio message published on the group's social media network, its first reaction since the launch of the U.S.-led strikes on Tuesday. (Reporting by Mariam Karouny, writing by Suleiman Al-Khalidi; Editing by Mark Trevelyan)

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