Tehran, June 8 (IANS): Four Saudi Arabian children on a pilgrimage to Iran died afer falling sick in their hotel rooms which had been fumigated, the Iranian health minister said on Monday.

Symptoms of pesticide poisoning were seen in the blood samples of the victims who were taken ill as a result of fumigation in the hotel where a group of 33 Saudi pilgrims was staying, Health Minister Hassan Hashemi said adding that four of them died on Sunday night, state run news agency IRNA reported.

The Iranian minister noted that the affected Saudi pilgrims received immediate and adequate treatment in hospitals in the holy city of Mashhad in Khorassan Razavi Province.

Urging an immediate probe into the incident, Hashemi called for severe punishment for those responsible for the incident, saying: "This is what the (Iranian) nation expects."

Abdollah Bahrami, head of the Imam Reza hospital in Mashhad, said the Saudi pilgrims were hospitalised with poisoning symptoms early on Sunday.

He added that four Saudi children lost their lives despite extensive treatment by the medical staff.

Mashhad Prosecutor Gholam Ali Sadeqi said a probe has been launched into the incident.

"A special inspector has been designated to immediately look into all aspects and probable causes of the incident," said the prosecutor.

Preliminary investigation rules out foul play in the deaths of the Saudi nationals, he noted.

Mashhad is the spiritual capital of Iran and it owes its significance to the Imam Reza shrine, which draws millions of pilgrims from around the world every year.