A series of explosions rocked Delhi on Saturday evening, killing at least 50 people and leaving 80 injured, 14 of them critically.

As many as 20 people have been killed in an explosion in Sarojini Nagar market and 15 others have reportedly been killed in Paharganj.

The markets were filled with shoppers doing their last-minute purchases for Diwali.

Most of those injured or killed in the explosions were ordinary people out shopping in the festival season.

Suspects detained

At least ten people have been detained following the three blasts in Delhi.

Five of them were picked up from the New Delhi Railway station and others from other railway stations and bus terminals.

It is now believed that high explosive devices suspected to be RDX were used in carrying out the blasts.

Prime Minister Manmohan Singh, in a statement from Kolkata said the blasts are a clear case of terrorism.

"No terrorist can win against India. India will win the battle against terrorism," the Prime Minister said.

Red alert sounded

A red alert has been sounded across several places in the country including neighbouring Punjab, Haryana, Uttar Pradesh, Mumbai and Kolkata.

Home Minister Shivraj Patil said it was too early to pinpoint who was responsible for the blasts.

"As to who is responsible for the blasts, we will not like to jump to any conclusion. The first priority is to give relief and succour to those affected by the blasts," the Home Minister said.

"We will enquire to ascertain who is responsible for this and why this happened," he added.

Congress President Sonia Gandhi visited the injured in hospitals. Extending her condolences to the families of those killed in the blasts, she described the incidents as acts of terrorism.

"Terrorism is a menace that we all have to face and fight together. This is not only a phenomenon here in our country. This is something that the whole world has to face. It is important that we all together fight it together," said Gandhi.

Series of blasts

People have been urged to remain calm and move away from crowded markets. Police have ordered all markets in the city to shut down.

The first blast took place in the main bazaar of Paharganj outside the New Delhi Railway Station at 5:38 pm (IST).

The explosion ripped apart the medical shop outside which the explosive device was planted, reportedly in a two-wheeler.

Scores of people have been injured in the explosion, eyewitnesses said.

"I was talking to a client when the blast took place. The blast took place about 20 metres away. Right after the blast, people were running here and there," said Sajjan Singh, shopkeeper, Paharganj.

"My son was right behind me, he was injured in the head and in the smoke I couldn't see where he fell," said Joseph George, another shopkeeper.

The police later barricaded the area and a shop-to-shop search was carried out for any more explosives.

Innocents killed

Around half an hour later, at 6:05 pm (IST), the second explosion took place in Sarojini Nagar market, one of the busiest in the Capital.

Diwali and Eid shoppers were making their last minute shopping when the bomb went off.

"There was a huge explosion as if LPG cylinders had gone off, it wasn't clear what happened. The market was very crowded," said an eyewitness.

Almost instantly, a fire broke out and spread quickly. Within minutes, the fire trucks reached the market and it took 45 minutes to bring the blaze under control.

"The market was completely crowded, there was no place to move. I was standing outside my shop when the blast took place. Ten people died immediately," said a shopkeeper.

Another explosion was reported from Govindpuri in south Delhi.

According to reports, the explosion took place inside a bus, and four people have been critically injured.