People evacuated from homes and several taken to hospital after 'chemical incident' in Alwold Crescent, Lee

Emergency services were called to Alwold Crescent amid fears residents may have suffered an allergic reaction.

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

Taxi driver Ian Crouch, 39, told the Sun that emergency services appeared to be investigating the sewage system.

Five fire engines, paramedics and police were all deployed to deal with the incident.

A spokesman for the Met Police said the incident was not believed to be crime-related.

Residents in four houses on the crescent were asked to leave their homes at around 11.30am and a cordon was erected.

Three fire engines were on the scene, as well as representatives from Thames Water, but the cause of the alleged chemical incident is still unknown.

Wayne Higgins, 50, said that he and his neighbours had been feeling unwell for the last few days.

"The fire brigade have been here checking if there are chemicals or toxins. For the moment we don't know when we will be allowed back in - not until they find out the cause of the problem.

"We just assumed everyone had a cold or something was going round."

Mr Higgins said they didn't start thinking it was a gas leak until yesterday evening.

Kevin Dobbins, 31, who was also asked to leave his home, said: "I haven't smelled anything or felt the effects myself. I know there were neighbours who were experiencing sickness and those who were smelling gas a few days ago.

"They did pull us all together and had a meeting with us saying you will have to leave the area and it could be throughout the night and into tomorrow.

"They are still uncertain. They have done checks and they've ruled out a few different things.

"They believe it could be a small gas leak."

A spokeswoman for the London Fire Brigade said: "We were called to the smell of chemicals and we've swept the area to check for raised levels (of gas or chemicals).

"We haven't found any raised levels and we are handing over to the gas board."

A spokeswoman for Southern Gas Network (SGN) said: "SGN is supporting the ongoing multi-agency response into the incident at Lee in south east London.

"Following reports of residents feeling unwell, around six properties were evacuated by the London Fire Brigade earlier. The situation is being investigated by the emergency services, utility companies and the local authority.

"As part of the ongoing investigation, SGN engineers are carrying out routine safety checks in the immediate area."