Commuters on the Blue Line of Delhi Metro had a harrowing time when a Metro train developed a technical problem and broke down at the Mandi House station.

There was heavy rush at the busy intersection connecting stations along the Blue Line to those on the Violet Line of the Delhi Metro Rail Corporation. It was not clear what caused the Metro train to malfunction.

Attempts were made to contact officials at the DMRC, the Mandi House Metro station and the helpline number but none were reachable.

READ | Man dies after falling on Delhi Metro track at Mandi House station

At the time of writing, some commuters had managed to board a train for Noida City Centre but the speed of the train on the route was extremely slow, according to a commuter.

A few commuters tweeted about the “technical problem”.

If you are planning to travel by Delhi Metro then avoid the blue line. It’s running too late due to technical problem as it is being said by officials.

— chandan Kumar (@chandan_charag) August 3, 2018

Why the hell is the World no longer at Sharda University?#RajivChowk #DelhiMetro #RushHour pic.twitter.com/swFL2Q5aDQ

— Shantanu Srivastava (@shantanu_kuks) August 3, 2018

I m standing at Mandi house metro station from last 40 minutes, metro is not working on blue line..both sides. No single announcement about delay at station …… huge crowd at platform. @DelhiMetro_

— kiran (@kiran11457514) August 3, 2018

The train, which broke down at Mandi House, was going towards Dwarka leading to a complete shutdown of the route.

Sources said the platform from where people were boarding trains to Dwarka had become overcrowded.

Meanwhile, the Central Industrial Security Force (CISF) launched a new electronic surveillance control room and security helpline number – 155655 – for Delhi Metro commuters.

The new helpline number will be integrated with the smart surveillance system that has been installed at the new command centre, named operational control centre-I (OCC-I).

“155655 will now be the new helpline. The old helpline number 22185555 will be discontinued in a few days,” said CISF spokesperson Assistant Inspector General (AIG) Hemendra Singh.

The CISF, which secures the Delhi Metro and over 200 operational stations in the national capital region, already has a command centre that functions from central Delhi.