Flash flooding in parts of south-west England following torrential rain has led to a major incident being declared in Somerset. Heavy thunderstorms on Tuesday evening resulted in Devon and Somerset fire and rescue declaring a major incident in the Galhampton, North Cadbury, and South Cadbury areas. Thunderstorms and heavy rain in other parts of southern England, including Devon, Hertfordshire, Northamptonshire and Essex, led to dangerous driving conditions, blocked roads, rail delays and damage to homes and businesses. The Met Office said showers forecast until Thursday could be heavy, with a risk of thunder and hail. Flood warnings have been in place since Tuesday night for the River Brue and Glastonbury Millstream between Lovington and Highbridge, with low-lying properties especially at risk. There are also flood warnings in Exeter, Sidmouth and Cullompton, according to the Environment Agency. Devon and Somerset fire service said it had deployed teams to support local people. It also asked local residents to avoid driving through floodwater, and for those who come into contact with it to decontaminate their bodies and clothing. The BBC reported that the village hall in north Cadbury was opened to residents on Tuesday night, and that about 18 households were thought to have been forced to evacuate. James Watts, the chairman of the village hall, told the BBC that the area had been cut off. “The water reached 4ft (122cm) in parts. The Parish Road end of the village is not as deep but there’s a torrent that is going across the road. It’s quite fierce,” he said. In Devon, the River Otter burst its banks, while Wilden All Saints school in Worcestershire was evacuated after it was hit by lightning. Tipton St John primary school and Woodbury Salterton primary school, both near Exeter, were affected by storms, Devon and Somerset fire and rescue service added. Hertfordshire constabulary tweeted on Tuesday night that it was experiencing a high volume of 999 emergency calls involving cars being stuck in flooded roads across Hertfordshire, in particular the eastern boroughs, following the afternoon’s downpour. Devon county council added that there were problems in Exeter “due to flooding and stuck vehicles”. Chilterns Railways reported cancellations and hour-long delays, while Greater Anglia cancelled services between Cambridge and King’s Lynn due to severe weather. Rescue services are asking anyone in an emergency situation involving floodwater to ring 999. An Environment Agency spokesperson said heavy thundery showers had resulted in “surface water flooding of several properties in parts of East Devon and Somerset overnight”. It is monitoring river levels and checking flood defences. He added: “Showers have been forecast for the next two days but as a precaution we urge residents to sign up for flood warnings and continue to monitor the weather reports. There has also been widespread disruption to roads and travel across the area so please check the road situation before setting off on a journey.”