Three co-ordinated bombings tore through the heart of India's busy financial capital during rush hour Wednesday, killing 21 people and wounding 141 in the worst attack in the country since the 2008 Mumbai siege.

Bloody bodies were strewn in the dirt of Mumbai's crowded neighbourhoods and markets. Doors were ripped off storefronts, motorcycles were charred and a bus stop was shredded. After the blasts in three separate neighbourhoods, police set up checkpoints and were put on high alert.

Arup Patnaik, a top police officer, said the attackers used improvised explosive devices in the bombings, hidden in an umbrella in the Jhaveri Bazaar jewelry market and kept in a car in the business district of Opera House.              

The third blast in Dadar area was caused by an explosive device concealed in an electric meter at a bus stop, the Press Trust of India news agency said.

Prime Minister Manmohan Singh condemned the blasts and appealed to the people of Mumbai "to remain calm and show a united face."

The bombings came just months after peace talks resumed between India and Pakistan, which New Delhi has blamed for past attacks.  

There was no immediate claim of responsibility, and Indian officials refused to speculate on who might be behind the blasts.

Indian officials have accused Pakistan's powerful spy agency of helping co-ordinate and fund earlier attacks, including the Mumbai siege, which killed 166 people over three days. Peace talks between the countries were suspended after the siege and resumed only recently.

Pakistan's government expressed distress about the loss of lives and injuries soon after Wednesday's blasts were reported.

Leaders condemn bombings

Prime Minister Stephen Harper called the attacks a "stark reminder that terrroism is alive and active around the globe and can strike at any time."

"On behalf of all Canadians, Laureen and I offer our deep and profound sympathy and condolences to the families and loved ones of those killed and injured by these heinous acts of violence, including Canadians who may have loved ones in Mumbai," Harper said in a statement.

"We offer our support as India works to bring to justice those responsible for these cowardly attacks against innocent people," Harper said.


A police officer stands guard at the site of an explosion in the Zaveri Bazaar, in south Mumbai, after a string of three bomb attacks. ((Danish Siddiqui/Reuters))

Federal Immigration Minister Jason Kenney said Canada is ready to offer assistance to India if help is requested.

A  Foreign Affairs spokesperson said officials from the department as well as the Canadian Consulate in Mumbai are closely monitoring the situation.

"At this point, we have no reports of Canadians being affected," Jean-Fran├žois Lacelle said Wednesday afternoon.

UN Secretary General Ban Ki-moon condemned the attacks, as did U.S. President Barack Obama.

"The American people will stand with the Indian people in times of trial, and we will offer support to India's efforts to bring the perpetrators of these terrible crimes to justice," Obama said in a statement. "I have no doubt that India will overcome these deplorable terrorist attacks."

U.S. Secretary of State Hillary Rodham Clinton said she will go ahead with her plans to visit India next week despite the bombings. Standing with India "is more important than ever," she said.

Opera House, Mumbai

The bombings began with an explosion that ripped through the famed Jhaveri Bazaar jewelry market at 6:54 p.m. A minute later, a blast hit the busy business district of Opera House, several kilometres away in southern Mumbai. At 7:05 p.m., the third bomb exploded in the crowded neighborhood of Dadar in central Mumbai, according to police.

Because of the close timing of the blasts, "we infer that this was a co-ordinated attack by terrorists," Home Minister Palaniappan Chidambaram said.

Bleeding victims crowded into the back of a cargo truck to be taken to a hospital, where wards were filled with the wounded, slathered in white burn cream.

At Jhaveri Bazaar, a witness described two motorcycles exploding in flames and saw at least six bodies.

"People were shouting 'Help me, help me,"' the man told Headlines Today television.

People hugged and wept. Crowds gathered in the blast areas as police questioned witnesses, and investigators wearing gloves sifted through the debris for clues.

"India is not going to cow down," cabinet minister Farooq Abdullah said. "Let those perpetrators of this terror remember, we will find them and Inshallah [God willing] we will give them the justice that India believes in."

The blasts marked the first major attack on Mumbai since 10 militants laid siege to the city for 60 hours in November 2008. That attack targeted two luxury hotels, a Jewish centre and a busy train station.

With files from CBC News