An ambulance carrying an elderly grandmother to hospital was stuck in floodwater on Oxford's Eastern Bypass as torrential rain brought chaos to Oxfordshire last night.

Houses were struck by lightning, buildings were flooded and vehicles became stranded in last night's electrical storm.

There was traffic chaos on the northbound stretch of the Eastern Bypass just south of BMW when an ambulance carrying Pamela Rivers, 79, of Cumnor, to Oxford's John Radcliffe Hospital got stuck in floodwater.

Mrs Rivers had felt ill after returning from holiday and her daughter Sarah Higton, 47, had been travelling with her. Mrs Rivers was transferred to another ambulance.

Traffic was backed up to the Littlemore Roundabout. HGVs were forced to wait by the side of the road on the northbound carriageway as police officers directed cars back up the carriageway.

Lorry driver Alistair Dewe, of Didcot, said: "I didn't have a clue what was going on. The traffic stopped and we were just told they weren't going to let HGVs reverse."

An ambulance service spokesman said last night: "We sent another ambulance to take the patient to hospital and the vehicle that got stuck is being recovered."

An Oxfordshire Fire and Rescue Service spokesman said: "There has been widespread flooding across Oxfordshire. It has just been chaos."

The fire service dealt with around 100 calls in a couple of hours as householders across the county reported flooding of their homes.

Fire crews were called to Sharp Laboratories, at Oxford Science Park, at 8.43pm.

The first and second floors of the laboratories were damaged by flooding, after a storm drain filled up. A fire broke out in the roof of a detached bungalow in Edinburgh Drive, Didcot, when it was struck by lightning.

Firefighters wore breathing apparatus as they extinguished the blaze, then used salvage kit to sheet the roof.

Lightning struck another home in Lambrick Way, Abingdon. The roof was damaged but there was no fire.

People at Oxford Stadium for the greyhound racing were forced to take cover as rain lashed through the restaurant ceiling.

The storm had already taken its toll on the 8.35pm race as the trap mechanism failed.

Conditions got worse as the ceiling tiles came crashing down. The meeting was abandoned soon after.

Roads on Oxford's Osney Mead Industrial Estate, off Botley Road, were waterlogged and a car was stuck under Botley Road Railway Bridge, which was flooded.