The incident happened during the busy evening hours here when constable Ravi Kumar of the CISF spotted the youth rushing dwon to the paltform area after picking a bag from the X-ray baggage scanner of the Metro station.
"The constable immediately sprung into action and apprehended the 18-year-old Vikas from the platform before he could take a train," CISF spokesperson Hemendra Singh said.
The bag belonged to a commuter Pankaj Suneja, resident of Om Vihar, who reached the CISF officials in the station and claimed ownership, after which it was returned to him.
The CISF has handed over Vikas, a resident of Budh Vihar, to Delhi police for further interrogation.
A CISF officer said they have been keeping a watch on such suspicious elements through their ground intelligence personnel in civil dress and even through CCTV surveillance especially in busy Metro stations like Chandni Chowk, Rajiv Chowk, Kashmere Gate and others.