Nine of the 10 planes operated by India’s IndiGo airline, which received a bomb threat on Wednesday, were checked but nothing unusual was found, a police official told Reuters.

One domestic flight that earlier landed in the Indian capital New Delhi from Jammu in the north was still being checked, said Dinesh Kumar Gupta, deputy commissioner of police at the capital's Indira Gandhi International airport.

IndiGo, an airline operated by InterGlobe Aviation Ltd., said in a statement that it had put in place additional security measures and all its passengers were safe. A spokeswoman said only three flights were searched.

The company had received a phone call about a bomb threat on some of its planes earlier in the day.

The bomb threats came a day after two brothers carried out suicide bombings at Brussels airport and on the Belgian capital's metro on Tuesday, killing at least 30 people. – Reuters