Tehran, June 10, IRNA � Foreign Ministry spokeswoman Marziyeh Afkham said Iran is sorry on what happened to a number of Saudi Arabian pilgrims in the holy city of Mashad.

Talking in her weekly press briefing, she further expressed sympathy with the families of the four pilgrims who lost their lives due to poisoning.

She noted that officials have been earnestly working on the case to discover the cause of the incident.

According to the spokeswoman, a number of people have been arrested in this connection.

Four Saudi citizens died from poisoning in a hospital in Mashad, in the northeastern Iranian province of Khorasan Razavi.

The incident happened on Sunday when a group of 33 Saudi pilgrims were hospitalized with poisoning symptoms.

Four Saudi children lost their lives despite extensive treatment by Iranian medical staff.

The Saudi pilgrims were staying at a hotel in the holy city of Mashad which houses the shrine of Imam Reza, the eighth Imam of Shiite Muslims.

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

Turning to the short visit of the Iranian Foreign Minister Mohammad Javad Zarif to Oman, Afkham said the visit took place to discuss a number of regional issues with Omani officials including the Yemen crisis.

She said the trip was short and compact but fruitful.

By IRNA