Ali Razini, head of Tehran's judiciary, was attacked by armed assailants while travelling in a car in the capital, Iran's official Islamic Republic News Agency (IRNA) said.

It said a motorcyclist hurled a hand grenade at Mr Razini's car as it was leaving his office in the Imam Khomeini Judicial complex in central Tehran.

Mr Razini was "slightly wounded" in the leg and taken to a hospital, IRNA said. His condition is reported to be satisfactory.

The attack killed another judiciary official and injured Mr Razini's driver and two other people, according to Iranian reports.

Nobody has admitted carrying out the attack, but in the past the armed opposition faction Mujahideen Khalq has claimed responsibility for similar incidents.

Hard-line conservative

Mr Razini, a hard-line conservative who heads the Special Court for the Clergy, is a key supporter of Iran's supreme leader Ayatollah Ali Khamenei.

Gholam-Hossein Karbaschi: Popular mayor sentenced to jail

He was the main person behind last year's trial of Tehran's popular mayor, Gholam-Hossein Karbaschi, who was sentenced to jail for corruption.

The attack comes four months after Mohsen Rafiqdoust, a senior economic official, survived an attempt on his life.

In August, the former head of Iran's prisons, Assadollah Lajevardi, was killed by gunmen in Tehran's bazaar.