MUMBAI, India — Indian officials called an emergency security meeting Thursday to investigate three coordinated bombings that killed at least 21 people in the country's financial capital in the worst terrorist attack since the 2008 Mumbai siege.
A steady drizzle Thursday morning washed away bloodstains and threatened evidence at the site of the attack Wednesday evening, which ripped off storefronts, shredded a bus stop and left bloody bodies strewn in the dirt of Mumbai's crowded neighborhoods and market.
Shellshocked residents lambasted the government for failing to detect the plot, despite massive security measures taken after the attacks three years ago that New Delhi has blamed on Pakistan-based Islamist militants.
No one has claimed responsibility for Wednesday's attacks, which came just months after peace talks resumed between India and Pakistan. Indian officials have so far refused to speculate on who might be behind the blasts.
Arup Patnaik, a top police officer, said the attackers used improvised explosive devices in the attack, 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 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 miles (kilometers) 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 coordinated attack by terrorists," Home Minister Palaniappan Chidambaram said in New Delhi.
Chidambaram later flew to Mumbai and visited the blast sites as forensic experts collected the evidence. Their task was hampered by a steady drizzle overnight washing away blood stains and other marks.
Investigators covered the blast sites with plastic sheets to protect the evidence left by the explosions, police officer Shailesh Kadam said.
Chidamabaram is scheduled to hold a security review meeting with the intelligence chief and top police officers in Mumbai later Thursday.
The government said the blasts killed 21 people and wounded 141 others.
As day broke Thursday, Mumbai began to return to normal life, with children holding umbrellas walking to their schools. Milk suppliers and vegetable vendors made rounds of the areas as municipal workers swept the streets.
Police and fire officers removed two dozen scooters and motorcycles from the jewelry market that were overturned and damaged by the impact of the powerful explosion.
Several people blamed complacency in the government for the attacks.
"After the 2008 blast and all the media hype (about safety) we thought we were safe. But things still are the same and people in Mumbai continue to feel vulnerable," said Anita Ramaswami, a 33-year-old accountant.
However, Ramaswami was not sure what the government should do.
Kumaresh Darde, another local resident, said police should go after criminal gangs, saying "Terror groups and the underworld may be working together."
Pakistan's government expressed distress about the loss of lives and injuries soon after Wednesday's blasts were reported.
Indian officials have accused Pakistan's powerful spy agency of helping coordinate and fund earlier attacks, including the 2008 Mumbai siege, which killed 166 people over three days. Peace talks between the countries were suspended after the siege and resumed only recently.
President Barack Obama also condemned the "outrageous 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.
A U.S. official said there were no immediate claims of responsibility nor any firm indication of which terrorist group might be behind the attack. The official spoke on condition of anonymity to discuss matters of intelligence.
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 center and a busy train station.
C. Uday Bhaskar, a defense analyst, said the bombings showed that Mumbai remained vulnerable despite precautions taken after the 2008 attack.
"The local police still does not have either the capability or the capacity to pre-empt such attacks, and this is going to be a constant challenge," he said.
The city has been on edge since the 2008 attack. In December, authorities deployed extra police on city streets after receiving intelligence that a Pakistan-based militant group was planning an attack over New Year's weekend.
In March 2010, Mumbai police said they prevented a major terrorist strike after they arrested two Indian men, who, police said, were preparing to hit several targets in the city. In September, police issued a terrorism alert for the city during a popular Hindu festival.
Last month, India and Pakistan held their first formal talks on the disputed region of Kashmir since the 2008 Mumbai attacks. Both nuclear-armed nations claim Kashmir in its entirety, and have fought two of their three wars over the region since they gained independence from Britain in 1947.
Associated Press writers Muneeza Naqvi and Ravi Nessman in New Delhi and Kimberly Dozier in Washington contributed to this report.