In a series of blasts and shoot outs, the city of Mumbai appears to have come under attack. According to the news, there appear to be at least seven different locations in the city that have been attacked. In an unprecedented sort of terror, a combination of gun fire, blasts, grenade blasts have been used to attack cinema halls, hotels, hospitals, and other public places. A mainsteam media report [1] states
At least four people are reported to have been killed and 15 are injured as unidentified groups of gunmen opened fire in at least four places across south Mumbai on Wednesday night.
In a one line post, a view on markets and life [2] evokes the confusion and shock of the event.
Sirens outside my window. Please make it a safe night.
On Twitter [3], several people are tweeting from Mumbai, and there appears to be very little information available. There is some amount of speculation if this is indeed a terror attack. Mumbai used to witness gang wars, but these haven't been heard of in a decade. 
[4]
An online community for engineers [5] posts the events as they happen
10 minutes before (10:45 PM IST) there is an Open Firing and Explosion reported in South Mumbai. Till now there is no Casualities reported. Atleast 15 Injured and 1 policeman injured. AK47 used in Firing .
So far 5 Confirmed Incidents reported in Shooting. 3 Confirmed Dead !
Firing reported in CST (Chatrapati Shivaji Terminal), Taj Hotel, Colaba Causeway and VT Station. Reports Confirmed its a Terror Attack. In VT Station atleast 15 people Feared Injured.
A post at Retributions [6] reminds us that the threat of terror is very real in India. A post at Staccato [7] articulates a similar thought – of the mindless terror attacks that have repeatedly struck various cities in India.
Bomb blasts in Bombay as we speak.
Phones jammed. Can't reach my family.
I've gone through this before.
Not panicking.
Another post echoes the fear [8] and helplessness.
it is extremely scary to watch all this on the news.
i'm immoderately shaking in fear right now. i never get so shaken up by news. it's the distance that's doing this. if i was in bombay i might not have been watching the news so carefully.
People in the city blog the sheer shock. The attacks have come at a late hour, and after the office rush hour. Himadri writes [9]
There was this friend of his who had just returned from Colaba. A firing had just occurred near Bade Miyan where he was eating. And as we were discussing and dialling random numbers on the cellphone, we heard three explosions within seconds or minutes of each other. The ground shook. This was not just another night.
We switched on the television. And the firing still goes on outside, in batches of 4-5 rounds. As I am writing this, there are sirens of vehicles, police vehicles echoing in my ear. There are 6 people in my living room now, watching the news. Two of them were sitting at Leopold, where there was a shootout earlier. One is a broker, and another one his friend. I am here, my roommate is here. Aunty is in her room, Babloo is cursing everyone to disturb his sleep. And We are together. Only unity can fight this.
Even as this post is being written, there are reports of more attacks and encounters in the city.