Roads closures and cordons in Gravesend have been lifted following Friday night's chemical gas drama.

A chemical used in expanding filler foam was behind the gas cloud, which brought hours of chaos to the town centre.

The substance causing the gas is called MDI isoscyanate, which is a component in expanding filler foam.

It was being used by contractors to repair a floatation tank on a floating pontoon at West Street Pier.

The resulting chemical reaction creates a gas which is classed as an irritant, and can cause breathing problems and irritate the eyes, although it is more likely to affect those with a pre-existing condition.

In response to the gas, emergency services closed a retail park and half a dozen roads.

Kent Fire and Rescue began reopening roads and lifting cordons just after 9pm and handed control back of the area around the pier to the site operators.

A spokesman for the fire service said: "It is likely that the chemical smell will remain in the air for several days, but it is not harmful."

People have reported a "horrid smell, like rotten eggy fish,' in the area and police have warned residents to stay inside and keep their doors and windows shut.

Kent Fire and Rescue Service said it is likely that the chemical smell will remain in the air for several days, but it is not harmful.

Anyone affected by the gas has been told to seek medical advice.

Imperial Retail Park was shut and the following roads were closed:

• Stewart Road at the junction with Overcliffe Road
• Baltic Wharf
• West Street
• Clifton Road at the junction with Bath Street
• Thames Way
• Clovesfield

Peter Stead, who lives near the pier, said earlier this evening: "We've been told to stay indoors and wait in case they evacuate us. Not sure about that but neighbours have left.

"Most residents have left anyway, and we've been told to be careful if we don't smell it anymore because it means we've got used to it."

Melvin Wilkie, landlord of the Rum Puncheon said: "We were told to stay in the pub and people were told to stay in their homes until the all clear was given."

Eyewitnesses said firefighters put on hazardous material clothing to investigate the gas.