TEHRAN — An Iranian passenger plane crash-landed on Sunday in thick fog in the northeastern city of Mashhad and caught fire, injuring at least 46 people, state television and other news networks said.

Iranian officials told local news networks that the rear end of the Russian-built Tupolev 154 plane owned by Taban Airline and piloted by a Russian caught fire as the aircraft landed in the fog.

"Forty-six people have been injured, but most of them are not serious," state television quoted Javad Erfanian, head of disaster management of Khorasan Razavi province of which Mashhad is the capital, as saying.

He said that emergency services evacuated the passengers after which the rear end of the aircraft broke up.

Pictures released by Iranian news networks showed both wings of the plane torn off and the rear end burning.

The English language state-owned Press TV said the plane, travelling from Abadan in southwest Iran to Mashhad, had 157 passengers on board. Erfanian said the plane also had 13 crew members on board.

An unnamed informed source told Fars news agency that the accident occurred as the Russian pilot landed the plane in the fog and its tail hit the ground and broke up.

The plane caught fire after passengers were evacuated, the report said as Press TV footage showed smoke billowing from the rear end.

Mohsen Esmaili, manager of Mashhad airport, told Mehr news agency that the pilot landed the plane in fog "despite repeated warnings from the control tower, saying he had a sick patient on board."

Reza Jafarzadeh, spokesman for Iranian civil aviation, said the plane had left Abadan on Saturday but bad weather in Mashhad led to the aircraft landing in the central city of Isfahan for the night before it took off again for Mashhad early Sunday.

"The captain had a critical patient on board and so had to do an emergency landing (in Mashhad) which is why the aircraft met with an accident," he was quoted as saying on the website of state television.

Iran, which has been under years of international sanctions, has suffered a number of aviation disasters over the past decade, several of them involving small companies using Russian crew or crews from former Soviet republics of Central Asia.

Iran's civil and military fleet is made up of ancient aircraft in very poor condition due to their age and lack of maintenance.

In its worst air accident, a plane carrying members of Iran's elite Revolutionary Guards crashed in February 2003, killing 302 people on board.

In July last year, a Soviet-designed Tupolev caught fire mid-air and plunged flaming into farmland northeast of Tehran, killing all 168 people on board.

In December 2005, a total of 108 people were killed when a Lockheed transport plane crashed into a high-rise housing block outside Tehran.

In November 2006, a military plane crashed on takeoff at Tehran's Mehrabad airport, killing all 39 people on board, including 30 members of the Revolutionary Guards.