印度孟买发生连环爆炸案

Amid popular anger and grief at the apparent terror attacks in India's financial hub, Mumbai, top Indian officials are heading to the city and promising answers.  At least 17 people were killed in Wednesday's back-to-back bomb blasts and dozens of others are being treated for injuries.

India's two most powerful political leaders arrived in Mumbai Thursday, as the country's mass media highlighted the anger and frustration at what many describe as the government's consistent failure over the years to protect the city.

Prime Minister Manmohan Singh and ruling Congress Party President Sonia Gandhi plan to visit hospitalized victims and inspect heightened security.  Singh said he understands the shock and anger felt by the city's inhabitants, and vowed to pursue those who planned the attacks "relentlessly."

The country's top national security official, Indian Home Minister P. Chidambaram, is also in Mumbai.  He says the government received "no intelligence input" that the attacks were imminent.  He says the blasts were caused by nearly a kilogram of improvised explosives.

"It appears that ammonium nitrate was used with a timer mechanism," Chidambaram noted.

Chidambaram offered no leads Thursday on who may be responsible for the attack, and says there will be no finger-pointing until police have conducted a thorough investigation.  He did make a more general statement blaming elements "hostile to India."

"The target is India's unity, integrity, and prosperity," Chidambaram added.  "There are elements that are hostile to India and do not want India to grow and prosper... and it is these elements which are behind the bomb blasts which have occurred for the last ten years."

Mumbai has been the target of a series of so-called "serial bombings" by terrorists over the last two decades.  This week's explosions mark the first apparent terrorist attack in the city since 2008, when gunmen killed 166 people at 10 hotels and other locations.

LK Advani, leader of India's opposition Bharatiya Janata Party, blamed the government for failing to keep Mumbai secure.  "This repeated attack on Bombay should be viewed as a policy failure," Advani said.

A senior Congress Party member, Rahul Gandhi, defended the government, saying it was impossible to provide completely airtight security.

"It is very difficult to stop every single terrorist attack.  We will stop 99 percent of terrorist attacks, but one percent might get through," said Gandhi.

India's External Affairs Minister SM Krishna confirmed that a visit by U.S. Secretary of State Hillary Clinton to the Indian capital, New Delhi, will proceed next week as scheduled.  Terrorism is expected to be high on the agenda as the two countries engage in a bilateral strategy dialogue.