487 people, including school students, teachers and residents of Tughlaqabad were hospitalized after a container of 2-Chloro-5-chloromethylpyridine leaked from a nearby depot. NDRF authorities managed to contain the leak.
Police said they have registered a case against unknown people, and dispatched a team to track down the container truck.
Several workers at the depot also fell ill because of the leaking fumes.
Delhi's gas leak incident
Over 50 students still in hospital
Police said along with 173 students, nine teachers had also been hospitalized.
About half were discharged after basic aid, but 59 students continue to remain under supervision; their condition is not said to be critical though.
Teams of the fire department, police, medical teams, and a Centralised Accident and Trauma Service unit reached the spot immediately after being alerted.
Police assure action for negligence
DCP Romil Baniya said the chemicals, brought in from China for industrial use and stored in containers at the depot, released toxic fumes.
Delhi Police and the National Disaster Response Force are trying to identify the substance.
Baniya added legal action will be taken for the "negligence as a hazardous substance was not handled properly".
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08 May 2017
Delhi Police yet to fix liability in gas leak incident
Officials disclosed that the chemical chloromethylpydrine was being loaded into trucks for being taken to Crystal Crop Protection in Sonepat; this, according to them, caused the leakage.
The police are yet to affirm the same. Investigations are underway.