At least 23 people have been killed after a fuel truck crashed into a flyover in the Saudi capital, Riyadh.

The crash triggered an explosion that brought down an industrial building and torched nearby vehicles, officials and state media said.

A Health Ministry spokesman said 135 people were injured in the blast.

The Civil Defence Department said a gas tanker had hit a bridge in eastern Riyadh, causing a gas leak and an explosion in a nearby heavy machinery and vehicles warehouse, according to the state news agency SPA.

Although the incident took place near the headquarters of the Saudi Arabian National Guard and the Prince Nayef Arab College for Security Sciences, officials speaking on state television said it was an accident.

The warehouse, several storeys high, was levelled by the blast, which also caused severe damage to other neighbouring buildings.

The blast, which struck at around 7.20am local time, was on one of the capital's busiest roads.

However, as Saudi Arabia is still observing the Eid al-Adha holiday, traffic was lighter than normal.