ISLAMABAD, PAKISTAN, AND NEW DELHI — India remains on edge amid reports of a threat of an attack by air, adding to people's fears of vulnerability after last week's brazen rampage by gunmen who landed on Mumbai's famed shoreline by boat.
Indian intelligence agencies warned Thursday of a possible hijack threat that would coincide with the anniversary Saturday of one of the most inflammatory events in India's recent history: the destruction of a centuries-old mosque in the north Indian town of Ayodhya by Hindu mobs in 1992. That incident has been an element of religious tension throughout South Asia.
Survivors of last week's attacks in Mumbai, which left more than 170 people dead, have been quoted as saying that at least one of the gunmen cited revenge for what happened in Ayodhya as a motive for their assault on luxury hotels and other busy spots in India's biggest metropolis.
Early today, Indian commandos combed New Delhi's international airport after reports that shots had been fired there. The cause of the scare remained unclear, but an airport official reached by telephone said that no one had been killed; an initial report by the British Broadcasting Corp. said Indian security forces had killed six gunmen.
The airport, which serves many international flights in the early morning hours, was operating normally by 3 a.m, Reuters news agency reported.
Although the threat of an airborne attack focused on the capital, New Delhi, and the southern cities of Bangalore and Chennai, formerly known as Madras, airports across the country went on high alert. Authorities added extra layers of security, including beefed-up patrols of armed guards and sniffer dogs and more thorough inspections of passengers and their belongings.
"We are prepared as usual," Air Chief Marshal Fali Homi Major, head of the Indian Air Force, told reporters.
That statement, however, was not likely to reassure many Indians, who have reacted with incredulity and growing anger to news that their government failed to act on repeated intelligence, including a warning from the United States, indicating that a terrorist attack on Mumbai by sea was possible. Tens of thousands of Indians have taken to the streets in protest, accusing the government of failing to protect its citizens.
Most of the investigation has focused on the lone captured suspect, who was seized after he and an accomplice allegedly fired indiscriminately into the crowd at a bustling railway station.
Investigators have said he has given details of the role of Lashkar-e-Taiba, saying the assailants trained at its camps in Pakistan. Investigators also allege that Zakiur Rehman Lakhvi, a senior Lashkar leader, helped mastermind the plot. Indian officials have also named another Lashkar leader, Yusuf Muzammil. Pakistan has said nothing about the charges, other than indicating it will not accede to India's demand to hand them over.
Indian news media reported today that an Indian suspected of having links to Lashkar-e-Taiba was arrested this year and found to have hand-drawn maps of some of the sites, which he apparently scouted out sometime last fall.
Secretary of State Condoleezza Rice, in a visit Thursday to Islamabad, said Pakistan "understands its responsibilities" in responding to terrorism in the wake of the attacks.
Rice said the sophisticated nature of the 60-hour assault underscored the need for a swift and thorough investigation.
"That means there is urgency to getting to the bottom of it," she said, " . . . to bringing the perpetrators to justice, and there is urgency to using the information to disrupt and prevent further attacks."
Rice, who visited India a day earlier, was publicly supportive of Pakistan's fledgling civilian government and its response to the attacks, telling reporters she was "quite satisfied" with her talks with senior government and military officials.
But a senior Pakistani official said the tone was tougher in private, with Rice emphasizing U.S. expectations that Pakistan aggressively pursue evidence against militant groups. A similar message was delivered a day earlier by the chairman of the Joint Chiefs of Staff, Navy Adm. Michael G. Mullen.
President Asif Ali Zardari reiterated a willingness to cooperate, his office said, pledging "strong action" against any Pakistanis found to have been involved in the attack.