Authorities in western India say as many as 100 people have been killed in seven explosions on commuter trains in the country's financial hub, Bombay.
Police say the blasts occurred in rapid succession during the evening rush hour Tuesday. They say the explosions were part of a well-coordinated attack. So far, no one has claimed responsibility.
Local authorities warned the death toll could go much higher, because the trains were packed with commuters.
The Associated Press quotes India's home minister as saying authorities had information that an attack was coming, but did not know the time or place.
After the blasts, Indian authorities put all major cities across the country on high alert.
Some information for this report was provided by AFP, AP and Reuters.