MUMBAI, (1st UPDATE) - Three explosions rocked crowded districts of India's financial capital of Mumbai during rush hour on Wednesday, killing at least eight people, media said, in the biggest attack on the city since 2008 assaults blamed on Pakistan-based militants.
At least 100 people were wounded in the near-simultaneous blasts, the home secretary said. Police earlier said at least three people had died.
One blast occurred at the Opera House, a tourist destination in south Mumbai near where Pakistani-based militants carried out the bloody rampage in 2008, killing 166 people.
Another blast, also in south Mumbai, was at the Zaveri Bazaar, the coastal city's diamond hub. The third blast was in the centre of the city.
CNN-IBN said police had told the broadcaster the blasts were caused by improvised explosive devices.
All three locations are crowded parts of the city, especially during rush hour.
India has remained jittery about the threat of militant strikes, especially since the Mumbai attacks in November 2008 which killed 166 people and raised tensions with arch rival Pakistan.
The Pakistan-based Lashkar-e-Taiba group, long focused on fighting Indian rule in Kashmir, was blamed for the coordinated attacks.
Television footage from CNN-IBN television channel showed debris of twisted metal, motorbikes and cars severely damaged at one suspected blast site.
"We were inside our office when we heard a huge noise. Outside there was a lot of commotion, we can see fire trucks are here and they have taken away two or three bodies," Jasraj Jain, a witness, told CNN-IBN television.
The popular Opera House area and Zaveri Bazaar were where two of the blast occurred. The third blast was in Dadar, which is in the centre of the city.
"I want the government to take immediate steps to investigate who were behind this," said Manohar Joshi, leader of Mumbai-based Shiv Sena political party, at one of the blast sites.
A reporter near the Opera House said police had cordened off the blast site and sent in sniffer dogs to examine the area. Ambulances and fire fighters stood by.
New Delhi says Pakistan-based groups aid and train militants to carry out attacks against India, a claim Islamabad rejects.
Home-grown militant groups are also active in the country and have in the past few years carried out attacks in large cities.
The home ministry ordered security heightened across the country.
Mumabi has over the years been the target of several attacks, including serial bomb blasts in 1993 that killed at least 260 people at the stock exchange and other areas.
In 2006, more than 180 people died when Islamist militants bombed commuter trains.