A senior Iranian official said Wednesday the aircraft carrying 168 people on board had technical problems before crashing into a field northwest of the capital and smashing into flaming pieces.

Senior IranIan provincial official, Sirous Saberi, said the aircraft had had technical problems and tried to make an emergency landing. Unfortunately the plane caught fire in the air and it crashed, he told the semi-official Fars New Agency.

While state radio said the pilot had made no mention of any technical problem in a taped conversation with a control tower.

It's been a major disaster with pieces of aircraft spread over an area of 200 sq meters, a fire brigade official said.

There was an explosion which left an indentation 10 meters deep in the ground. There was nothing we could do. We tried to put out the fire as best we could, he told state television.

The Caspian Airlines Tu-154M aircraft had taken off from Tehran's Imam Khomeini International Airport on Wednesday morning and was headed to the Armenian capital Yerevan.

It crashed about 16 minutes after takeoff near the village of Jannat Abad outside the city of Qazvin, around 75 miles northwest of Tehran, civil aviation spokesman Reza Jafarzadeh told state media.

On board the plane there were 151 adults, 2 children and 15 crew members, Caspian Airline's representative in Yerevan Arlen Davudyan told Reuters at the airport. All passengers were killed.

Hossein Ayaznia, an aviation police official, said emergency workers were searching for the plane's data recorders to get evidence of the cause.

It was the worst aircraft crash in Iran for six years.