A bomb attack Thursday on a train in the Indian city of Chennai has reportedly left a pregnant woman dead and a further nine passengers injured.

The train, an express service traveling from Bangalore to Guwahati, was rocked by an explosion while it was held in the Chennai station at around 7:30 am local time.

The bombs resulted in explosions on two separate carriages of the train. The explosions occurred under the passenger seats, and were described Thursday as "low intensity" by officials talking to the BBC.

The woman who died in the blast has been identified as 24-year-old Swati Shah, from Andhra Pradesh. According to One India, she was eight-months pregnant.

A further two passengers are in critical condition, according to IBTimes UK.

Two people have been detained in connection with the explosions, but officials have not speculated on the reasons for the attack or the identity of the attacks. Police Chief JK Tripathi did, however, suggest the bombs could have been detonated using a "basic mobile device."

Senior railway official Rakesh Mishra added that "the entire police force is involved" in the investigation into what happened.

India is currently celebrating the May Day holiday, one of the biggest holidays in the country's calendar, and millions of people are travelling around the country to take part in the festivities.

The attacks come just hours after a man set himself on fire during a TV debate about India's ongoing national elections.