JEDDAH: Saudi Arabia has urged its citizens to be extra cautious while traveling to Iran and asked Tehran to expedite its investigation into the death of four Saudis as a result of chemical poisoning while staying at a hotel in Mashhad.

“The issue is still under investigation amid the lack of clarity and mysterious circumstances surrounding it,” said a Foreign Ministry spokesman about the case that also left 29 injured.

“The ministry has called upon Saudi citizens traveling to Iran to take utmost caution to preserve their safety and security from any harm,” the spokesman added. Saudi Arabia also urged Tehran to give necessary protection to its citizens in Iran.