Iran protests against Saudi Arabia
Policemen clash with demonstrators during a protest against Saudi Arabia after a crush in which at least 155 Iranians were killed at the hajj pilgrimageReuters

Iran has promised to take international legal action against Saudi Arabia's rulers as tensions continue to mount over the deadly Hajj stampede. Iran has also demanded an apology from Saudi Arabia, prompting a strong backlash from the Kingdom, which accuses its rival of playing politics with the tragedy.

Pandemonium broke out on 24 September when two crowds of pilgrims converged upon a narrow street to take part in the stone-throwing ritual, leading to the worst disaster during the annual visit in the past 25 years. Seen as one of the five pillars of Islam, all healthy adult Muslims must complete the Hajj pilgrimage once in their lifetime, providing they have the financial means and are physically able to do so. Over two million Muslims from 180 countries make the spiritual journey each year.

"Under international law, this incident is absolutely subject to prosecution. The Al-Saud must be responsive," Iran's State Prosecutor Sayed Ibrahim Raisi told state television. Referring to the ruling family, he added: "They have to know that we will pursue the trial of Al-Saud for the crime they have committed against the hajj pilgrims through international courts and organisations."

Tensions between the Sunni and Shi'ite nations continued to mount as Iran's supreme leader, Ayatollah Khamenei, said Saudi Arabia should apologise, while President Hassan Rouhani called for an investigation into the catastrophe during a speech at the UN in New York. Angry protestors in Iran chanted "death to the Saudi dynasty".

"This issue will not be forgotten and the nations will pursue it seriously," Ayatollah Khamenei said. "Instead of accusing this and that, the Saudis should accept the responsibility and apologise to the Muslims and the victims' families."

"The Islamic world has a lot of questions. The death of more than 1,000 people is not a small issue," he added in a mention to claims made by Iranian officials of a higher death toll.

Saudi Foreign Minister Adel al-Jubeir has dismissed criticism from the country's bitter rival, with the two nations locked in regional proxy wars. "I believe that the Iranians should know better than to play politics with a tragedy that has befallen people who were performing their most sacred religious duty," he said.

The Saudis have been backed by the country's top cleric in the hostile fallout from the event, who said he did not hold authorities responsible for the crush. "You are not responsible for what happened," Grand Mufti Sheikh Abdul Aziz bin-Abdullah al-Sheikh told the country's Crown Prince Mohammed bin Nayef, who is also chairman of the Supreme Hajj Committee.

"You dealt with the beneficial factors that were in your hands and within your ability. As for the things that humans cannot control, you cannot blamed for them. Fate and destiny are inevitable."

Iran has said 155 of its citizens were killed in the crush, reportedly the highest total across all countries. Over the weekend, Saudi Arabia said the death toll had risen to 769 people but that number has been vehemently contested by Iran's Fars News Agency, which reported: "A stampede during one of the last rituals of the Hajj season killed more than 2,000 people and left 2,000 wounded."