Police officials said that they had issued warnings of a possible terrorist attack in the city and had stepped up surveillance.
The biggest companies in the sector -- Waste Management Inc. of Houston, Allied Waste Industries of Scottsdale, Ariz., and Republic Services Inc. of Fort Lauderdale, Fla .-- have recently issued warnings of revenue and earnings shortfalls.
But it is far from alone: two other chip makers, United Microelectronics of Taiwan and General Semiconductor of the United States, also issued warnings of weak second-quarter results.
The weather office has issued warnings of "severe heat wave" conditions across large parts of India's northern and western regions through the weekend.
Mr. Ashcroft has issued warnings of new terrorist threats, based on vague but credible intelligence information, overruling some reluctant F.B.I. officials.
The prospect of all the reactors going offline has alarmed the business community and the nation's powerful nuclear lobby, which have issued warnings of the dire economic consequences if nuclear power is lost.
Mr. bin Laden, who has a $5 million American reward on his head, recently issued warnings of fresh attacks on American targets through a videotape delivered to an Arab-language satellite television channel in Qatar.
In the past week David Cameron, MI6 and the London police have all issued warnings of the "danger to Britain" from this month's Isis invasion of northern Iraq, and from a possible 400-500 "returning jihadists".
