Hundreds of ambulances rush to help those wounded in the crush - which comes just two weeks after a deadly crane collapse.
Some 4,000 rescue workers and 220 ambulances are involved in the emergency operation, officials said.
Pictures on social media showed a devastating scene, with dozens of bodies lying among water bottles and crushed wheelchairs.
Mina is where pilgrims go to carry out a symbolic stoning of the devil by throwing pebbles against stone walls.
Witnesses said the stampede happened on Street 204, one of
the main roads leading through the camp set up for pilgrims to get to
the three stone walls, known as Jamarat.
More than 160,000 tents are set up in the area.
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One unnamed pilgrim said he had been planning to perform the stoning ritual in the afternoon but was too frightened to do so.
"I am very tired already and after this I can't go. I will wait for the night and if it not resolved, I will see if maybe somebody else can do it on my behalf," he said.
The deaths come on the first day of Eid, traditionally the most hazardous day of the Hajj because so many people are trying to perform rituals at the same time.
It also comes less than two weeks after a giant crane crashed down on the Grand Mosque in Mecca, the site which is the focal point for the pilgrimage.
At least 111 people died then and more than 390 were injured.
The last time so many people died at the Hajj was in 2006 when at least 346 pilgrims were killed in a stampede in the same area
The pilgrimage lasts for five days.
It is seen as a religious duty for able-bodied Muslims to complete the Hajj at least once in their lifetime and take part in the rituals intended to cleanse their souls and promote the brotherhood and sisterhood of Islam.
David Cameron has tweeted: "My thoughts and prayers are with the families of those killed at the Hajj pilgrimage."
At least 717 people have died and hundreds more are injured after a stampede on the edge of Mecca, Saudi authorities say.
Civil defence officials said more than 800 were also injured
in the crush at Mina, on the outskirts of the Muslim holy city, where
some two million people are at the annual pilgrimage.Some 4,000 rescue workers and 220 ambulances are involved in the emergency operation, officials said.
Pictures on social media showed a devastating scene, with dozens of bodies lying among water bottles and crushed wheelchairs.
Mina is where pilgrims go to carry out a symbolic stoning of the devil by throwing pebbles against stone walls.
More than 160,000 tents are set up in the area.
"I am very tired already and after this I can't go. I will wait for the night and if it not resolved, I will see if maybe somebody else can do it on my behalf," he said.
The deaths come on the first day of Eid, traditionally the most hazardous day of the Hajj because so many people are trying to perform rituals at the same time.
It also comes less than two weeks after a giant crane crashed down on the Grand Mosque in Mecca, the site which is the focal point for the pilgrimage.
At least 111 people died then and more than 390 were injured.
The last time so many people died at the Hajj was in 2006 when at least 346 pilgrims were killed in a stampede in the same area
The pilgrimage lasts for five days.
It is seen as a religious duty for able-bodied Muslims to complete the Hajj at least once in their lifetime and take part in the rituals intended to cleanse their souls and promote the brotherhood and sisterhood of Islam.
David Cameron has tweeted: "My thoughts and prayers are with the families of those killed at the Hajj pilgrimage."