The International Civil Aviation Organization (ICAO) warns against speculation about the causes of the catastrophe of the Ukrainian liner in Iran until the investigation is completed, RIA Novosti reported.

The organization’s leadership stresses the need to refrain from any speculation about the reasons for this tragedy until the end of the investigation in accordance with Appendix 13 to the Convention on International Civil Aviation (Chicago Convention), the ICAO statement said.

ICAO maintains contacts with relevant states and will assist them if such a request is received, the organization added.

ICAO leadership expressed condolences over the disaster.

Ukrainian plane crashed shortly after leaving Tehran's airport early Wednesday morning. According to official figures, all 176 people died: 167 passengers from Iran, Ukraine, Canada, Germany, Sweden and Afghanistan and nine crew members.