Officials in India's financial capital, Mumbai, say parts of the city remain under siege, hours after teams of heavily armed attackers began an unprecedented, ongoing assault on numerous locations.
About 80 people are confirmed dead, with some of the city's top law enforcement officers among those killed, including Mumbai's anti-terror chief, Hemant Karkare.
Hospitals are filled with casualties, and authorities say at least 200 have been wounded so far.
Police say gunmen with automatic weapons and grenades have attacked at least nine different places in a highly coordinated series of terror attacks. The sites include two train stations and two luxury hotels - The Taj Mahal Palaceand the Oberoi - as well as hospitals, Leopold's, a restaurant popular with tourists, and a dockyard.
Flames and plumes of smoke billowed from the Taj Hotel. Army commandos moved into that luxury hotel before dawn Thursday.
Security forces and gunmen are engaged in a standoff at the Oberoi.
Authorities say gunmen are believed to be holding hostages in the hotels, but the number of hostages is not yet known.
Authorities also say four gunmen have been killed and nine arrested, but it is not clear where these encounters occurred.
A British man, Rakesh Patel who escaped from one of the hotels told local television that attackers specifically wanted people with British or American passports.
The motive for the assault is not immediately clear. Local media report a previously unknown militant group, called the Deccan Mujahideen, has claimed responsibility for the attacks. It is not clear if the claim is credible.
The railway inspector general in Mumbai, KP Raghuvanshi, says the attacks are terror-related.
Islamic militants have been blamed for past bombing attacks.
India's Home Minister Shakeel Ahmed says the main priority is to overpower the attackers.
A member of parliament from southern Mumbai, Milind Deora, says the explosions were caused by grenades, not bombs. But witnesses say the gunmen also fired indiscriminately.
Some information for this report was provided by AFP, AP and Reuters.