The Saudi Foreign Ministry has summoned Iran's Ambassador to Riyadh Hossein Sadeghi after four Saudi pilgrims died from poisoning in the northeastern Iranian city of Mashhad.

Saudi Foreign Ministry spokesman Osama Naqli said in a statement on Tuesday that the ministry expressed deep concern over the incident and hoped the Iranian authorities would urgently take the necessary investigations and discover all circumstances surrounding it, the Saudi Press Agency reported.

Naqli added that the Saudi embassy in Tehran immediately contacted with the Iranian Foreign Ministry and the concerned authorities in Mashhad to follow up the issue.

According to Iran's Health Minister Hassan Hashemi, the incident on Sunday happened as a result of fumigation in an apartment hotel in the holy city of Mashhad in Khorasan Razavi province where a group of Saudi pilgrims were staying.

The Saudi nationals were hospitalized with poisoning symptoms. Four Saudi children lost their lives despite extensive treatment by Iranian medical staff and 28 others were injured.

Iran’s Judiciary spokesman Gholam Hossein Mohseni-Ejei said on Monday that five people had been arrested over the incident.

“Interrogation of the hotel’s staff and officials started immediately and five people are currently under arrest,” Mohseni-Ejei said.

He added that no evidence showing the incident was intentional has been found yet, stressing, “However, this statement is not definite.”

Mashhad is the spiritual capital of Iran and home to the Imam Reza shrine, which attracts millions of pilgrims from around the world every year.

SF/MHB/AS