Attack on Masjid al Haram : Terrorist in mecca,fake mahdi

“On this day in 1979, during the annual Hajj pilgrimage, Islamic dissidents led a brazen armed attack on the Grand Mosque in Mecca, one of Islam’s holiest sites. The siege lasted two weeks, took hundreds of lives, and shocked the Muslim world.The extremist insurgents calling for the overthrow of the House of Saud took over Masjid al-Haram in Mecca, Saudi Arabia.
The insurgents declared that the Mahdi (the "redeemer of Islam") had arrived in the form of one of their leaders – Mohammed Abdullah al-Qahtani – and called on Muslims to obey him.
In all, there were close to 500 militants led by two men, Juhayman al-Oteibi, a fundamentalist preacher and former member of the Saudi National Guard, and Mohammed Abdullah al-Qahtani, who claimed to be the Mahdi, or messiah.

uhayman had turned against al-Baaz "and began advocating a return to the original ways of Islam, among other things: a repudiation of the West; abolition of television and expulsion of non-Muslims." He proclaimed that "the ruling Al-Saud dynasty had lost its legitimacy because it was corrupt, ostentatious and had destroyed Saudi culture by an aggressive policy of Westernization."
Al-Otaybi and Qahtani had met while imprisoned together for sedition when al-Otaybi claimed to have had a vision sent by God telling him that Qahtani was the Mahdi. Their declared goal was to institute a theocracy in preparation for the imminent apocalypse. They differed from the original Ikhwan and other earlier Wahhabi purists in that "they were millenarians, they rejected the monarchy and condemned the Wahhabi ulama."

The insurgents also had sniper which were placed at minars (pillars of entrance gate) who were taking out the Saudi militants each time they tried to enter in the masjid 

Enforcement

Pakistan provided 50 Pakistani SSG commandos as re-enforcement

A team of three French commandos from the Groupe d'-    intervention de la Gendarmerie Nationale (GIGN) arrived in     Mecca.Because of the prohibition against non-Muslims   entering the holy city, they converted to Islam in a brief,    formal ceremony.the three GIGN commandos trained and equipped the Saudi forces and devised their attack plan (which consisted of drilling holes in the floor of the Mosque and firing gas canisters wired with explosives through the perforations), but did not take part in the action and did not set foot in the Mosque. He claims that Pakistani SSG commandos carried out the operation instead.

Taking back the haram

Tanks were used to get into the mosque. Tanks rammed into the walls of masjid, as a result, the insurgents backed off due to heavy forces entering into the masjid.the remaining insurgents along with  Mohammed Abdullah al-Qahtani took shelter in the basement present in the masjid the advantage that they got here was they was only one way in and out so as soon any commando try to enter the basement they can easily shoot at them.
Many different ways were used to get them out like pumping gas into the underground chambers and  ,Saudi forces drilled holes into the courtyard and dropped grenades into the rooms below, but none worked very well. At last the basements were filled with water and current of high voltage was used leading to the death of  Mohammed Abdullah al-Qahtani and surrender of all the other militants.

What happened to the Rest

Al-Qahtani was killed in the recapture of the mosque but Juhayman and 67 of his fellow rebels who survived the assault were captured. Saudi courts secretly tried the surviving militants, then, on the orders of King Faisal, publicly executed 67 of the men in public squares across eight Saudi cities.”