US President Barack Obama has extended by one more year the national emergency with regard to certain type of terrorist attacks. In his notification, Obama said, because the terrorist threat continues, the national emergency declared on September 14, 2001 , and the powers and authorities adopted to deal with that emergency must continue in effect beyond September 14, 2011 .Meanwhile, the US intelligence agencies and security forces are currently on a manhunt for three men believed to be planning massive terror attacks in America to coincide with the 10th anniversary of the 9/11 attacks.According to Senator Joseph Lieberman, the manhunt was launched following “credible and specific” information that the trio would be carrying out terrorist attacks with explosive laden vehicles in cities like New York and Washington , which has forces authorities to elevate the threat level nationwide.Multiple media reports said the threat involved a car-or truck-bomb attack aimed at bridges or tunnels in the two cities.