More than 700 were killed and 800 were injured in a stampede in Saudi Arabia during the annual Islamic pilgrimage to Mecca.

The stampede happened just 2 miles from Mecca during the final ritual known as Mina, or "the stoning of the devil."

The Saudi king has expressed his condolences over the tragedy and pledged a speedy investigation.

King Salman also said Thursday that he has given instructions for a review of "all existing plans and arrangements...to improve the level of organization and management of the movement" of pilgrims at the hajj.

Meanwhile, Iranian Supreme Leader Ayatollah Ali Khamenei urged Saudi authorities to accept their responsibility for the tragedy, saying it was caused by "mismanagement."

Khamenei offered his condolences to families and relatives of the victims and announced a three-day mourning period. Dozens of Iranian pilgrims perished in the stampede.

In New Jersey, Ken Abuassab, founder of the American Arab Civil Association, says he attended the ritual a few years ago. Mina is often considered to be one of the most dangerous rituals.

"It's just because so many people come together in one spot on that day. That day is over 2.5 million people," Abuassab says.

Apollo Travel and Tours in Paterson says the hajj package is one of its most popular tours. Nearly 40 New Jersey residents are in Saudi Arabia through Apollo's tour. Travel agent Willie Ammar says that most of their group is OK.

"I spoke to our group leader this morning because a lot of people called me, asking about what happened. Things are OK," he says.

About 1,800 New Jersey residents are believed to be in Saudi Arabia for the pilgrimage. Many are expected to return next week.