WASHINGTON - US President Barack Obama has reviewed potential threats to the United States before next week's anniversary of the killing of Osama bin Laden, but there is no concrete evidence al-Qaida is plotting any revenge attacks, the White House said on Thursday.US Navy SEALs shot bin Laden last year in a raid on the al-Qaida leader's compound in Pakistan before dawn on May 2 local time, which was May 1 in the United States. The killing is touted by the Obama administration as one of its top national security accomplishments."At this time, we have no credible information that terrorist organizations, including al-Qaida, are plotting attacks in the United States to coincide with the anniversary of bin Laden's death," White House press secretary Jay Carney said on Thursday.That assessment was echoed in an FBI and Department of Homeland Security intelligence bulletin issued on Wednesday to state and local law enforcement agencies.The bulletin said US agencies did "assess that al-Qaida's affiliates and allies remain intent on conducting attacks in the Homeland, possibly to avenge the death of bin Laden, but not necessarily tied to next month's anniversary."It added that individuals had "posted messages threatening unspecified attacks in the Homeland that coincide with the anniversary on violent extremist Web forums." But the bulletin added that "such threats are almost certainly aspirational."Carney said that Obama reviewed the "threat picture as we head into the anniversary of the bin Laden take-down," and he emphasized the risk of revenge by al-Qaida remained real.News of the demise of the man behind the Sept. 11, 2001, attacks on New York and Washington was widely celebrated in the United States. But it fanned anti-American sentiment in the Muslim world, particularly Pakistan, which was deeply embarrassed by the raid inside its own territory. The New York Police Department also said it was unaware of any threat related to the bin Laden killing anniversary."But the NYPD continues to maintain a robust counter-terrorism posture regardless of anniversaries because of past and repeated interest demonstrated by terrorists in returning here to kill New Yorkers," said Paul Browne, the department's chief spokesman.