CHENNAI - Twin bombs planted on a train killed at least one person and wounded nine others on Thursday in the main southern Indian city of Chennai, police and government officials said.
The explosion, which comes as India holds a mammoth general election, occurred in a carriage of an overnight train from Bangalore as it pulled into Chennai central station, a railway official said.
A 22-year-old woman was killed when one of the devices which had been placed underneath her seat exploded shortly after 7:00 am (0130 GMT), said Rakesh Misra, general manager of the southern region for Indian Railways.
"At least two people have suffered grievous injuries and seven have minor injuries," Misra told reporters in comments aired on Indian television.
"Civil police... are investigating what kind of bomb it was and why anyone could have placed the bomb." Police said one suspect has been detained in connection with the "low-intensity" blasts and he was being questioned, according to the Press Trust of India (PTI) news agency, quoting police sources.
Police, bomb disposal squads and sniffer dogs were seen searching the carriages of other trains at the station, while the platform was cordoned off.
One panic-stricken passenger told PTI that he saw three to four people "writhing in pain" after the blast.
Security has been tightened across India as the country holds a six-week general election which has been marred by deadly violence in other parts of the country, including attacks by Maoist rebels.
Voting has already taken place in most major cities, including Chennai which went to the polls last week.
K Ramanujam, police director general in Tamil Nadu state, of which Chennai is the capital, said the city may not have been the target of the blasts because the train was running late.
"It is premature to say what kind of device was used in the blast. Damage to the train is not heavy," he said.
Although the motive for the bomb blasts is unclear, local militants have staged a string of attacks in recent years. Sixteen people were killed last February when local outfit the Indian Mujahideen exploded two bombs strapped to bicycles in the city of Hyderabad.
Tamil Nadu Chief Minister Jayalalithaa Jayaram "strongly condemned" the blasts and urged people not to panic.
Families of the victims will receive compensation, Railways Minister Mallikarjun Kharge told reporters. The train was expected to continue its journey once the affected carriages were detached.