Improving connectivity between pilgrim centres and helping local economies are at the centre of the government's push for Vande Bharat Express trains, sources said on Friday.

With Prime Minister Narendra Modi set to flag off the semi high-speed modern train between Secunderabad and Tirupati on Saturday, four of the 13 operational Vande Bharat Express routes will connect some of India's most revered pilgrimage sites, the government sources said.