Beirut - Islamic militants and their supporters celebrated the death of Saudi King Abdullah on social media on Friday, many of them describing him as a "servant" of the Americans who conspired with the West to kill Muslims.Abdullah, who died at the age of 90, began battling al-Qaeda militants around a decade ago when extremists launched a string of attacks in the kingdom aimed at toppling the monarchy. Backed by the kingdom's top ally, the United States, Saudi officials responded with a massive crackdown and has imprisoned suspected militants and sentenced others to death."The thief of the two holy mosques has died," wrote a militant supporter on Twitter. "He lived and died as a servant to America," posted another.Many Islamic extremists consider the Saudi royal family to be corrupt and unfit to rule. The Islamic State group, an al-Qaeda breakaway group that currently holds a third of Iraq and Syria, often cites Islam's holiest city of Mecca in Saudi Arabia, as one of its targets.Saudi Arabia is also part of a US-led coalition targeting ISIS in airstrikes.A jihadi supporter who goes by the name of Abu Azzam al-Najdi criticized the late king saying: "He sent his warplanes to kill Muslims in [Syria]. He imprisoned Muslim men and women and wherever there was a war against jihadis, he was the first."Loyalists of al-Qaeda and ISIS alike organised their comments under hashtags, some that translate from Arabic into "Death of a Tyrant".Another jihadi supporter who goes by the name of Omar wrote in English: "The dog that was occupying [the land of the two holy shrines] has finally kicked the bucket, no Bush or Obama to save you from Allah."One user posted a photo illustration of King Abdullah wearing an orange uniform as a masked man stood behind him carrying a knife to behead him."We don't want him to die. We want to slaughter him this way," the post said, referring to Saudi Arabia's tradition of beheading criminals.