By Sanjoy Majumder
BBC News, Delhi
Hours after a series of attacks across the Indian capital, an uneasy calm has gripped the city.
Security has been stepped up across large areas of Delhi
Large areas of Delhi are under a tight security blanket - one of the heaviest seen in years.
Policemen armed with assault rifles and automatic weapons can be seen patrolling key intersections and key installations.
Many of them have been placed outside government buildings and even at the entrances of the city's shiny new metro rail stations.
One of the city's main hospitals, the All India Institute of Medical Sciences, has a tight security cordon around it.
This is where many of the blast victims were brought in, dazed, bleeding and crying for help.
Delhi's hospitals are treating scores of people injured in the blasts
"Some of the injuries are horrific," one of the doctors on duty told us.
"We have cancelled all leave. We need every medical worker on duty to help out at this time."
One of the blasts took place in Paharganj, a crowded neighbourhood at the very heart of Delhi.
A tightly packed warren of narrow lanes filled with shops and cheap hotels, it is popular with Western backpackers as well as Indian shoppers.
This Saturday, it was especially full ahead of the festival season. Next week is Diwali, the Hindu festival of lights, and the Muslim festival of Eid.
It is a time when markets such as these are filled to bursting with shoppers, out for last-minute purchases of fruits, candies, gifts and firecrackers.
The markets themselves are gaily decorated, with brightly coloured lights and festoons.
Piyush Solanki runs a cyber cafe, some 200m (650ft) from where the first blast occurred.
"I thought a firecracker had gone off," he recalls.
"The next thing I know, the windows of my shop were shaking. I ran out, to find the whole place covered in black smoke.
"As the smoke cleared, I saw the body of a young woman lying on the ground. The blast had ripped her clothes off."
As news of more attacks came in, panic set in.
Shopkeepers downed their shutters and within minutes entire markets emptied out.
Many people have been left shocked and scared by the attacks
What only a short time ago had been cheerful, bustling markets were now eerily silent neighbourhoods, filled with tense, gun-toting security men.
Across town, in the high-security government district, a series of white official cars with flashing red beacons pulled up in front of the interior ministry.
Tight-lipped security and intelligence officials rushed in for the first of many high-level meetings.
It has been years since Delhi has seen an attack of this magnitude and intensity, and the security establishment were quite clearly shaken by the day's events.
Outside, as darkness fell, a feeling of insecurity long forgotten has returned to haunt the city's residents.
"This is what it used to be like in the '80s," says long-time Delhi resident Bharti Singh, recalling the days when Delhi was hit by a wave of Sikh militancy.
"We thought it was behind us."