Poor weather conditions are thought to have contributed to a plane crash in Iran on Sunday which claimed at least 77 lives.

A Boeing 727 operated by IranAir was on route from Tehran when it came down and broke into pieces near the city of Orumiyeh.

As many 104 people were on board when it crashed, with two passengers still missing and 25 injured, some critically.

Local reports suggest the aircraft was delivered to IranAir in 1974 and was the oldest passenger aircraft operating in the country.

The plane was due to land in Orumiyeh, 430 miles north-west of Tehran.

In an interview with the ISNA news agency Ahmad Majidi, the head of the road and transport ministry’s crisis panel, said bad weather was the cause of the crash.

“Based on the evidence, the plane’s captain could not land at Orumiyeh airport due to bad weather conditions and he decided to return to Tehran,” he explained.

“But for unknown reasons the plane crashed around five miles from the airport.

“We do not know if the two missing are among the fuselage’s debris, or in hospital, or dead. We will find out about them today,” he added.

State TV said the aircraft disappeared from radar and went down in farmland after making a second attempt to land at the airport in the north-western city of Orumiyeh.

The nature of the technical failure was not clear.