The alleged operative Liaqat Ali, who hails from Kupwara in Jammu and Kashmir, was on way to Delhi in a train when he was arrested from Gorakhpur Railway Station, police sources said.
He was produced in a court yesterday which sent him to police custody for 15 days.
Sources claimed that he told them that some weapons were kept for him in a guest house in near Jama Masjid area in Central Delhi.
Police are on the lookout for more operatives who might have sneaked into the city.