Saudi Arabia has deported more than 520 Iranian pilgrims, claiming that the visas they used to the enter the country are fake, Radio Free Europe reports.
The move comes just ahead of hajj, an annual pilgrimage in that Muslims from all over the world travel to.
Tensions between Saudi Arabia and Iran have been high since the United States reported that Iran was behind a plot to kill the Saudi Ambassador to the US.
One of the deported pilgrims told Iran's Fars news agency that the visas were issued by the Saudi Consulate in Mashhad, and were not fake.
He added that the pilgrims were told that "the majority of Iranians are Jewish or have Jewish ancestors and there is no reason for them to go on hajj pilgrimage."
Earlier this week, Iran's Deputy Foreign Minister Hassan Qashqavi shrugged off the deportations, saying that the Mashhad consulate had experienced difficulties issuing visas prior to hajj. Qashqavi was negotiating with Saudi officials to resolve the issue, and has reportedly encouraged Saudi officials to introduce visa-free travel during hajj.
Prince Nayef bin Abdul-Aziz warned that Saudi Arabia would employ all means during hajj to deal with any unrest in the country, Press TV reported.
In July 1987, violent clashes between Saudi security forces and Iranian Shiites resulted in the deaths of over 400 people, including 275 Iranians, Radio Free Europe reported.
The incident resulted in Iranians attacking the Saudi Embassy in Tehran, and Iranian supreme leader Aytollah Ruhollah Khomini called on the Saudis to over throw the ruling Saud family in revenge for the pilgrim's deaths. Iran boycotted hajj for the next three years.
Tensions between Saudi Arabia are again at a high following allegations that IRan was behind a plot to kill the Saudi Ambassador to the United States.
Iran has denied involvement in the alleged plot.
Iran had earlier stated that they hoped hajj would be "very calm" despite the tensions between the two countries.
There are 2.5 million pilgrims attending hajj this year, 97,000 of whom are Iranian.