The United Nations says nearly 300,000 Rohingya refugees have arrived in Bangladesh since attacks by Rohingya militants on Myanmar security forces in the violence-wracked Rakhine state on August 25 sparked a major military backlash.

The 57-member OIC, meeting in Astana, expressed "serious concern about recent systematic brutal acts committed by the armed forces against the Muslim community of Rohingya in Myanmar."

It urged Myanmar to accept UN monitors to carry out "a thorough and independent investigation of all established violations of international human rights.. and bring those responsible to justice".

The current OIC chief is Turkish President Recep Tayyip Erdogan, who has been one of the loudest critics of Myanmar's policies against the Rohingya.

The Rohingya are reviled in Myanmar, where the roughly one million-strong community are accused of being illegal immigrants from Bangladesh.

Iranian President Hassan Rouhani and Afghan leader Ashraf Ghani were among the other heads of state who attended the summit hosted by Kazakhstan and the Central Asian country's veteran autocrat Nursultan Nazarbayev.

The plight of the Rohingya has triggered broad international condemnation of Myanmar and the country's Nobel peace prize laureate leader Aung San Suu Kyi.