VIENNA, Austria — From papal prayers to telegrams from China, the world reacted with an outpouring of compassion yesterday for victims of Hurricane Katrina in messages tinged by shock that a disaster of this scale could occur in the United States.

Islamic extremists rejoiced in America's misfortune, giving the storm a military rank and declaring in Internet chatter that "Private" Katrina had joined the global jihad, or holy war. With "God's help," they declared, oil prices would hit $100 a barrel this year.

Venezuela's government, which has had tense relations with Washington, offered humanitarian aid and fuel.

The storm was seen as an equalizer — proof that any country, weak or strong, can be victimized by a natural disaster. Images of flood-ravaged New Orleans earned particular sympathy in central Europe, where dozens died in raging floodwaters days ago.

"Nature proved that no matter how rich and economically developed you are, you can't fight it," said Danut Afasei, a local official in Romania's Harghita county, where flooding killed 13 people last week.

Throughout Europe, concerned citizens lamented the loss of life and damage caused to New Orleans, often described as one of North America's most "European" cities.

French President Jacques Chirac and German Chancellor Gerhard Schroeder sent messages of sympathy to President Bush.

Pope Benedict XVI said he was praying for victims of the "tragic" hurricane while China's President Hu Jintao expressed his "belief that that the American people will definitely overcome the natural disaster and rebuild their beautiful homeland."

Britain's Queen Elizabeth II also sent a message to Bush saying she was "deeply shocked and saddened" at the devastation.

The U.S. Embassy in Bern, Switzerland, said calls were rushing in from Swiss individuals and institutions looking to donate to relief efforts.

"We are getting calls from the Swiss public looking to express their condolences, [and] people are also asking for an account number where they can make donations," spokesman Daniel Wendell said.

Amid the sympathy, however, there was criticism.

Experts in the Netherlands expressed surprise that New Orleans' flood systems failed to restrain the waters.

With half of the country's population of 16 million living below sea level, the Netherlands prepared for a "perfect storm" soon after floods in 1953 killed 2,000 people. The nation installed massive hydraulic sea walls.

"I don't want to sound overly critical, but it's hard to imagine that [the damage caused by Katrina] could happen in a Western country," said Ted Sluijter, spokesman for the park where the sea walls are exhibited.

The sympathy was muted in some corners by a sense that the United States reaped what it sowed, since the country is seen as the main contributor to global warming.

Joern Ehlers, a spokesman for World Wildlife Fund Germany, said global warming had intensified hurricanes.

"The Americans have a big impact on the greenhouse effect," Ehlers said.

But Harlan Watson, U.S. envoy for negotiations on climate change, denied such a link.

"Our scientists are telling us right now that there's not a linkage," he said in Geneva. "I'll rely on their information."

Associated Press reporters Susanna Loof in Vienna, Bradley S. Klapper in Geneva, Alexander S. Higgins in Geneva, Anca Teodorescu in Bucharest, Romania, and Toby Sterling in Amsterdam contributed to this report.