New Delhi: Five persons, including three children, who were ragpickers, died after being trapped in a roadside drain in southwest Delhi's Chhawla area on Sunday.

They might have died of suffocation due to harmful gases inside the drain or drowned in the sludge, a police official said.

The police are trying to find out why the children entered the drain. The deceased have been identified as Sahidul (10), Safikul (9), Hasidul (26), Afsae Ali(30) and Lalsun (12).

This morning, Sahidul, Safikul and Lalsun were roaming near the drain. According to some people, Sahidul and Lalsun entered the drain as they had seen some beer bottles floating in it. Only some portion of the drain is covered, the officer said.

When the duo did not come out of the drain for a long time, Safikul informed Sahidul's father Hasidul and Lalsun's uncle Ali. The trio jumped inside the drain to rescue Sahidul and Lalsun but got trapped inside, police said.

When the five people were not spotted for a long time, locals rushed to the spot and found the bodies floating in it.

Following this, they informed the fire department and the police.

By the time the Fire department personnel reached the spot, the locals had already pulled out the persons and rushed them to a hospital where they were declared brought dead, police said.

"The families of the deceased have been informed. The bodies have been sent for post-mortem," they said.

Preliminary investigation suggests that the five persons might have drowned after fainting due to extreme heat and gas inside the drain, the police said.

A case has been registered in the matter and police will send a notice to the Public Works Department in the matter.