The call, however, later turned out to be a hoax.
According to CISF sources, a call was received at DMRC's helpline number around 10:15 am. The caller, who had called from a mobile number, told the receiver about a bomb in a metro.
Soon after getting the call, CISF, Delhi Police and DMRC officials swung into action and initiated anti-sabotage measures. Metro stations and trains were thoroughly checked but nothing suspicious was found.
"As twin bomb blasts had taken place early in the morning in a train at Chennai railway station, we were extra cautious in our approach but the call was found to be hoax," a police official said.
When the number was traced and investigators reached the address given while procuring the number from which the call was made, the address was found to be fake.
"The address provided to buy that number was found to be wrong. Efforts are on to nab the accused," said Deputy Commissioner of Police (Railways) Sanjay Bhatia.
Officials said that train operations remained unaffected due to the call.
"There was a little delay on Inderlok-Rithala line around 11 AM, but that took place due to a signal problem," an official said.
Delhi Metro officials declined to give any official response, saying that it's a security issue and only CISF and police officials can comment on it.