Islamic Republic of Iran and the republic of Turkmenistan in a ceremony in Mashhad on Thursday signed a protocol on environment protection and coordination to fight oil pollution in the Caspian Sea.Iranian vice-president and head of the department of environment Mohammad Javad Mohammadizadeh and Turkmen Minister of Environment Babagaldi Anabaei Ramov were the signatories of the protocol. Mohamadizadeh said on the sidelines of the ceremony that the protocol is signed along an adopted document of Tehran Convention for Caspian sea littoral countries. He said that Iran and Turkmenistan enjoy common cultural and historical grounds, they pledge to protect their territorial waters in the Caspian Sea from any pollution especially oil pollution. Anabaei Ramov thanked Iran for the endeavors made in environment fields and called for further cooperation in this respect.