Residents were told to keep their windows closed after a strong-smelling liquid was spilled on the motorway.

Motorists suffered long delays on the coastbound carriageway on the M20 last night after the suspected chemical spill.

Police were called to junction 13 at Folkestone near the Channel Tunnel just before 9pm after a report of an "unknown fluid" on the road.

Witnesses reported a strong smell and a specialist team from Kent Fire and Rescue Service was called.

Those living nearby were asked to keep their windows closed as a precaution while the substance was tested to see if it was harmful.

A police spokesman said: "The M20 was closed from junction 12 while the situation was assessed.

"Following tests at 1.10am it was confirmed the fluid was not hazardous and the road was cleaned and reopened."

Highways England later described it as a fuel spill.

Social media reports suggested it was diesel.

Motorists also had to cope with delays because the motorway was closed between Ashford junctions 9 and 11 for routine maintenance.