New Delhi, May 31 -- The toll in the Saidulajab building collapse near Saket Metro Station here rose to six on Sunday, officials said.

Several others have sustained injuries in the tragic incident that has raised fresh concerns over building safety and unauthorised construction in the national capital.

The multi-storey commercial structure, which housed coaching centres, offices and eateries, came crashing down on Saturday during ongoing construction work on its upper floor. Rescue teams worked through the night to pull survivors from the debris and recover those trapped beneath the rubble.

According to officials, a nearby tin-shed canteen popular among students preparing for medical entrance examinations was also buried under the fallin...