Image copyright Reuters Image caption PM Narendra Modi flagged off the Vande Bharat Express on Friday

India's fastest train has broken down on its first trip, a day after it was inaugurated by Prime Minister Modi.

The Indian-built semi high-speed Vande Bharat Express was returning to the capital Delhi from the city of Varanasi after its first outing when brakes in a carriage reportedly jammed.

Indian media quoted a railways spokesperson as saying the train may have struck cattle on the line.

The train reached a speed of 180km/hr (110mph) during trials.

Soon after the brakes failed, the drivers noticed smoke in the last four coaches and power was lost in all compartments.

Those on board, mostly railway officials and journalists, had to take another train to get back to Delhi.

Despite the railway ministry's suggestion that the train may have hit a cow, NDTV reported that there were no signs of damage on the front of the train after the incident.

The new train service is expected to start its commercial run from Sunday. It is expected to reduce the travel time between Delhi and Varanasi by six hours.