Saudi Arabia's King Abdullah
Saudi Arabia's King Abdullah arrives at Heathrow Airport in west London, Oct. 29, 2007. Reuters/Dylan Martinez

Islamic militants and their supporters took to social media on Friday to celebrate the death of Saudi Arabia’s King Abdullah, describing him as “the thief of the two holy mosques,” according to The Associated Press. Abdullah died at the age of 90 after battling pneumonia.

Some of the Islamic militants reportedly called Abdullah a "servant" of the Americans and claimed that he had conspired with the West to kill Muslims. Abdullah began his fight against al Qaeda nearly a decade ago when the Islamist militant group launched several attacks in the kingdom, which, with the help of the U.S., launched a massive crackdown on the group. Saudi officials reportedly jailed several suspected militants and sentenced many others to death.

"[Abdullah] lived and died as a servant to America," a militant supporter reportedly wrote on Twitter.

The Islamic State group, formally announced last month that it hopes to conquer Saudi Arabia, which is also part of a U.S.-led coalition targeting the ISIS.

"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,” a jihadi supporter identified by the name of Abu Azzam al-Najdi said, according to AP, while another wrote: "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."

Some of the comments from the supporters of al Qaeda and ISIS were posted under Arabic hashtags, which meant "Death of a Tyrant," AP reported.