At least 453 people have been killed in a stampede at the annual Hajj pilgrimage, Saudi Arabia's civil defense directorate said, as the death toll continued to rise.

The directorate said at least 719 other pilgrims were injured in Thursday's stampede, which took place in Mina, on the outskirts of the holy city of Mecca.

The injured have been evacuated to four different hospitals in the Mina region, according to a civil defense spokesman.

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.

"During and after the stampede the pilgrims continued to flock into Mina to perform the devil stoning ritual."

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 alongside crushed wheelchairs and water bottles.

The head of the Central Hajj Committee, Prince Khaled al-Faisal, blamed the stampede on "some pilgrims from African nationalities," Saudi-owned al-Arabiya TV channel reported.

Survivors assessed the scene by standing on the top of roadside stalls as rescue workers in orange and yellow vests combed the area.

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

PHOTO CAPTION

An ambulance drives towards the camp city at Mina, September 24, 2015.

Al-Jazeera