Washington/New Delhi:
As the United States and the world mark the tenth anniversary of the 9/11, there's a global alert against fresh terror attacks.
In US, there is heightened security after President Barack Obama extended the emergency declared there after the 9/11 attacks to another year, and in the wake of fresh intelligence on possible terror attacks from suspected Al Qaeda members.
In India, there's been an alert right since the Delhi High Court blast on Wednesday in which 13 people died. Security is particularly tight in malls and markets.
After a meeting of the National Investigation Agency (NIA) on Saturday on the blasts, shopping complexes have been asked to ensure they have adequate number of security cameras installed.
"The investigation on Delhi blast is still going on. We have got some reports from forensic laboratories. There are also various emails sent by different groups and we are investigating each. Interrogations are going on," Union Home Secretary RK Singh said.
AP adds: US intelligence agencies have found no evidence that Al Qaeda has sneaked any terrorists into the country for a strike coinciding with the 10th anniversary of the September 11 attacks, senior officials said on Saturday.
But authorities kept a high alert as investigators looked for proof of a plot possibly timed to disrupt events planned in Washington or New York on Sunday.
Since late Wednesday, counter-terrorism officials have chased a tip that Al Qaeda may have sent three men to the US on a mission to detonate a car bomb in either city.
At least two of those men could be US citizens, according to the tip.
No intelligence supported that tip as of today, and officials continued to question the validity of
the initial information.
While such tips are common among intelligence agencies, this one received more attention, and government officials chose to speak publicly about it, because of the connection to the anniversary of the worst terrorist attack in US history.
Al Qaeda long has hoped to strike again on the anniversary. At the FBI field office in Washington, assistant director James McJunkin described the tip and the response as routine.
The US already had bolstered security nationwide before the upcoming anniversary and anticipated an increase in tips.
"We expect we're going to get an increase in threats and investigative activity around high-profile dates and events," he said. "This is a routine response for us."
Intelligence analysts have looked at travel patterns and behaviours of people who recently entered the country. While they have singled out a few people for additional scrutiny, none has shown any involvement in a plot, according to the senior US officials, who insisted on anonymity to discuss the investigation.