At least 310 people have been killed in a stampede at the annual Hajj pilgrimage, Saudi Arabia’s civil defence directorate said.

The directorate said at least 450 other pilgrims were injured in Thursday’s stampede, which took place in Mina, on the outskirts of the holy city of Mecca.

Mina is where pilgrims carry out a symbolic stoning of the devil by throwing pebbles against three stone walls. It also houses more than 160,000 tents where pilgrims spend the night during the pilgrimage.

Al Jazeera’s Basma Atassi, reporting from Mina, said the incident took place in a street between pilgrim camps.

“The street where it happened is named Street 204. This stampede did not happen at the site of the ‘stoning of the devil’ ritual, which was happening today.”

Where the stampede took place. pic.twitter.com/UprkxcaAk5
— Basma Atassi | بسمة (@Basma_) September 24, 2015

Amateur video shared on social media showed a horrific scene, with scores of bodies – the men dressed in the simple terry cloth garments worn during Hajj – lying amid crushed wheelchairs and water bottles along a street.

Survivors assessed the scene from the top of roadside stalls near white tents as rescue workers in orange and yellow vests combed the area.

About 4,000 rescue services personnel were participating in the operation to help the injured and about 220 ambulances were directed to the scene, a civil defence spokesman said.

#منى pic.twitter.com/Q2jW3mSFYw
— hicham messaoudi (@prohicham) September 24, 2015

Photos released by the directorate on its official Twitter account showed rescue workers helping the wounded onto stretchers and loading them onto ambulances near some of the tents.

Al Jazeera’s Omar Alsaleh, reporting from Mecca, said the number of deaths may rise.

“This is only the initial number … The Hajj season was already overshadowed by the crane accident that killed 107 people and wounded more than 200,” Alsaleh said, adding: “The area has turned to a big massive construction site to allow more pilgrims to visit Mecca during Hajj.

“Mina has more than 160,000 tents divided over several camps, and with the 1,9 million people taking part in this year’s Hajj, you will understand the logistical nightmare that the Saudi authorities are facing.”

Deadly Hajj incidents

Saudi authorities take extensive precautions to ensure the security of the Hajj and the safety of pilgrims. But tragedies are not uncommon.

In 2006, more than 360 pilgrims were killed in a stampede at the desert plain of Mina, where pilgrims carried out the symbolic stoning of the devil ritual.

The day before the 2006 Hajj began, an eight-story building being used as a hostel near the Grand Mosque in Mecca collapsed, killing at least 73 people.

Mina now. #hajj2015 Follow updates on stampede here http://t.co/GgLg8siUOO pic.twitter.com/imCeF7P3lk
— Basma Atassi | بسمة (@Basma_) September 24, 2015

Two years earlier, a crush of pilgrims at Mina killed 244 pilgrims and injured hundreds on the final day of the Hajj ceremonies.

In 2001, a stampede at Mina during the final day of the pilgrimage ceremonies killed 35 pilgrims.

The worst hajj-related tragedy, which occurred in 1990, claimed the lives of 1,426 pilgrims in a stampede in an overcrowded pedestrian tunnel leading to holy sites in Mecca. Al Jazeera