The fears about an incident during the conventions or later in the year have also led state and local officials to impose extraordinary security precautions. Persistent if indistinct intelligence reports, based on electronic intercepts and live sources, indicate that Al Qaeda is determined to strike in the United States some time this year, the officials said in interviews last week.

New York is regarded as a higher risk than Boston by counterterrorism officials because President Bush is a Republican and because of consistent intelligence.

"Al Qaeda has unambiguous plans to hit the homeland again," James L. Pavitt, the C.I.A.'s outgoing head of clandestine operations, said in a speech in New York last week, "and New York City, I am certain, remains a prime target."

Some of the information has indicated that potential attackers might not be young Arab men, but religious extremists from other countries, possibly in Africa. For that reason investigators have begun to more closely examine visa holders already in the United States from countries like Somalia, Kenya and Nigeria.

Agents from the Federal Bureau of Investigation are also starting to conduct interviews in communities where potential terrorists might seek to blend in with local populations. The officials said that the interviews were based on intelligence about who might pose a threat, but would also be patterned on the informational interviews conducted in Arab-American neighborhoods after the Sept. 11 attacks and in Iraqi-American communities at the start of the American-led invasion in 2003.



http://www.nytimes.com/2004/07/05/politics/05SECU.html?pagewanted=all&position=