"All city shops will remain closed," said Sitaram Jaiswal, convener of the Joint Traders Association.
Local traders also sought an audience with Uttar Pradesh Chief Minister Yogi Adityanath, who has represented his hometown of Gorakhpur in the Lok Sabha since 1998.
A 45-year-old trader, identified as Chandra Prakash Tibdewal, was on his way home, from his office premises in the city's Sahebganj region, when his scooter was intercepted at Deewan Bazar by some people riding motorbikes. The attackers shot the trader dead and fled with cash worth Rs 20 lakh, which Tibdewal was carrying.
The police said that the trader was rushed to a hospital, where he succumbed to his injuries while undergoing treatment.
The police further said that members of Tibdewal's staff are being questioned and vigil has been stepped up in the city.
Chief Minister Yogi Adityanath, who is also in-charge of the home department in the state, has formed a special cell to personally monitor crime in the state, Uttar Pradesh Energy Minister Shrikant Sharma said today.
"A special cell will be constituted in the Chief Minister's office for crime monitoring, which will be done personally by the chief minister," Mr Sharma said.
(with inputs from Agencies)