An excavator being carried on a trailer hit the bottom of the bridge spanning Aldo Moro Road in Marsa, paralysing traffic and even affecting air transport.

The accident happened just before 1 p.m. and the road, which connects Malta's south to the rest of the island, was closed in both directions as Transport Malta civil engineers assessed the visibly damaged bridge.

The ensuing traffic led to six Air Malta flights being delayed as passengers and crew were stuck on the road to the airport. A number of cruise passengers who were meant to leave at 6 p.m. were stranded in Santa Lucia for a while, although they did eventually make it to the ship on time. The Education Department had to postpone the Matsec oral exams of students who were stuck in traffic.

While the southbound carriageway was reopened for traffic at about 3.30 p.m., the one taking traffic to Valletta was only opened on two lanes during rush hour, throwing the south of the island into chaos.

Traffic was at a standstill as far as Mqabba and Ħal Far, forcing many to wait for over four hours.

Even though traffic policemen were out in full force, many complained traffic was not being well managed.

Timesofmalta.com readers reported that two ambulances and a fire engine were stuck in the traffic although Mater Dei Hospital later said no urgent cases had been affected.

Many said they changed their plans for the afternoon or simply got out of the vehicle in which they were passengers and walked to their destination.

After spending almost two hours on the road, a passenger on the delayed Air Malta flight to Heathrow, who until a few days ago feared the flight would be cancelled because of the volcanic ash, said: "The volcano couldn't stop us but a fool of a driver almost did".

It is not yet known how serious the damage to the bridge is.