Concern is growing for several groups of British pilgrims who have not made contact with their families since the stampede that killed more than 700 people in Saudi Arabia.
The Muslim Council of Wales said it knew of around 120 people in three groups from Cardiff, Newport and Swansea who were unaccounted for.
A spokesperson told Sky News other members who travelled to Mecca for Hajj had made contact to say they were safe but there had been no word from the missing pilgrims, and their phones were not connecting.
The Foreign and Commonwealth Office (FCO) has not yet confirmed whether any British pilgrims are among the 719 people killed and 863 injured, but a spokesperson said it was “urgently gathering information”, with staff searching hospitals and hotels.
Dr Hojjat Ramzy, an imam and director of the Oxford Islamic Information Centre, is one of the many families and friends anxiously awaiting news of their loved ones.
“I’m looking for a couple of my friends, I can’t get in contact with them,” he told The Independent. “I’m hoping they are alive and they just can’t get to their phones.”
Dr Ramzy is a survivor of the worst ever Hajj-related tragedy in 1990, when 1,426 pilgrims died in a stampede inside an overcrowded pedestrian tunnel leading to holy sites in Mecca.
“There was so much pressure, I couldn't breathe and I could see the people toppling down,” he said.
“I had to put my feet on people’s heads because I was being pushed forward. I wasn't in control.
“A lady was in front of me screaming ‘don’t push, don’t push’ but within five minutes she fell down and died.”
The imam, who was 35 at the time, managed to clamber to safety and launched a complaint with Saudi authorities about crowd control.
“I told them they had to do something. It’s not safe and it’s never going to be safe until they rectify their procedures,” Dr Ramzy said.
“These people died miserably and somebody is responsible. I believe it’s the government. If millions of people are coming to your country you need to look after them.”
The governments of Saudi Arabia, Iran, Afghanistan, Egypt, India, Turkey, Indonesia, Kenya and Pakistan have all said their citizens are among the dead.
Witnesses said security forces had forced two masses of people to clash by closing several paths through Mina, near the holy city of Mecca, while some Saudi officials sought to blame “some pilgrims who didn't follow the guidelines issued”.
One group of devotees had been making their way towards the Jamaraat Bridge, a large structure used by pilgrims to throw stones at three walls as part of the symbolic “stoning of the devil” ritual, while other pilgrims were leaving when the crowds met on Thursday morning.
Some Saudi officials sought to blame “some pilgrims who didn't follow the guidelines issued” and a statement from the country’s London embassy said: “The majority of Thursday's victims descended onto a pathway toward Jamarat during a time that was not allocated to them.”
Authorities have introduced successive rounds of safety measures after successive disasters during the Hajj but critics say they do not go far enough.
As well as stampedes, there have been deadly fires, violence and road accidents.
The latest tragedy came just two weeks after a giant construction crane came crashing down on the Grand Mosque in Mecca, the focal point of the Hajj.
The FCO urged worried relatives in the UK to contact its switchboard on 020 7008 1500. Anyone in Saudi Arabia can contact the British Embassy on +966 11 4819 100, or go to the FCO's website or Twitter for information.