Fears are growing about a chemical incident in south London after residents were rushed to hospital and families with children evacuated from their homes.

Emergency services were called to Alwold Crescent just before 10am today amid fears locals may have suffered an allergic reaction.

Witnesses said a number of people suffered a reaction to an unknown substance yesterday morning. 

Seven adults and two children were evacuated from their homes and assessed by paramedics.

Two of them were rushed to hospital, while 12 others living at surrounding properties were also forced to leave, according to the London Fire Brigade.   Taxi driver Ian Crouch, 39, told The sun that emergency services appeared to be investigating the sewage system.

He told the newspaper: 'I could see the emergency services outside my house.

'When I spoke to a policeman he said there were people complaining of irritation, who had been throwing up all morning. 

'He said they were investigating whether it is terror related, but told us not panic. 

'They think it's coming from the sewage system. Five fire engines, paramedics and police were all deployed to deal with the incident.

A Metropolitan Police spokesman said the incident is not believed to be crime-related and the investigation is being led by the London Fire Brigade.

A fire spokesman said: 'We were called to Alwold Crescent in Lee at 9.53am.

'We reviewed a row of terraced houses and maisonettes after residents reported smelling an unknown chemical.

'We carried out a sweep using specialist equipment but had no elevated readings.

'Responsibility for the incident has now been passed to the water and gas authorities who are carrying out an investigation.' 

The London Ambulance Service was called to the scene just over an hour later at 11.05am and confirmed they checked over nine people, two of which were sent to hospital.