Residents have been allowed to return home following a suspected "chemical incident" in south-east London that left two people in hospital.
Emergency services were called at 09:50 BST on Sunday over fears residents in Alwold Crescent, Lee were suffering reactions to an unknown chemical smell.
Gas firm SGN said it completed routine safety checks in the area on Sunday and had found no abnormal gas readings.
Greenwich Council said it was trying to establish the cause of the irritant.
Nine people were assessed by paramedics after reports of nausea and vomiting, and two of those assessed were taken to hospital.
Twenty one people were evacuated from their homes as a precaution at about 11:30 on Sunday.
London Fire Brigade (LFB) said it had swept the area but found no raised levels of chemicals or toxins.