Muslim pilgrims surging forward to take part in an Islamic ritual ignored instructions from security forces, setting off a stampede that killed more than 100 people, a top Saudi security official was quoted Friday as saying.

The victims, most of them elderly, were trampled or plunged to their deaths during the chaos Thursday in Mina, about three miles from Mecca. One elderly Moroccan woman's head was crushed in the stampede, one doctor said.While the official death toll was 118, government sources speaking on condition of anonymity put the actual count at more than 150.

The tragedy is part of a string of stampedes, fires and other bloody accidents that have marred the Muslim holy journey to Mecca in recent years.

Before the crush began Thursday, police had been restraining crowds outside the area where pilgrims partake in the "stoning the devil" ritual, in which pebbles are thrown at three pillars symbolizing the temptations of Satan.

When security forces began to let pilgrims through, people in the crowd of about 700,000 began to press forward, setting off the stampede, Gen. Ahmad Bilal, director general of public security, was quoted as saying by the Arab News.

"The number was frightening and the crowd advanced like a torrent," the English-language paper quoted him as saying.