Suspected plots to wage New Year’s Eve violence led to an arrest in New York state and raids in Belgium, as security agencies around the world imposed extraordinary measures amid heightened fears following attacks in Paris and California.

From Sydney Harbor to the Rose Bowl parade, authorities expanded patrols Thursday, blocked off several traditional celebration spots and had security teams operating at some of the highest threat levels.

Police in the German city of Munich evacuated two train stations, urged people to avoid crowds and warned of a possible imminent attack just before midnight.

Bavarian Interior Minister Joachim Herrmann and Munich police chief Hubertus Andrae said German authorities had been tipped off by a foreign intelligence service that the Islamic State terrorist group was planning attacks with five to seven suicide bombers, but so far no arrests had been made.

Despite police warnings, thousands of people were on the streets of Munich at midnight to welcome the new year with fireworks, the Associated Press reported.

Belgium has increased its security threat level in the capital city of Brussels, after the arrest of two in connection with a possible New Year's Eve attack plot. (Reuters)

In western New York, the Justice Department said a 25-year-old man, Emanuel Lutchman, was arrested after allegedly planning to attack a restaurant in Rochester, N.Y., in coordination with an Islamic State member in Syria contacted online.

Lutchman, described as a self-professed Muslim convert, apparently planned to use knives and similar weapons for the assault, according to a Justice Department criminal complaint made public Thursday.

[FBI: Alleged attack plotter wanted to kill “innocent civilians”]

Lutchman, who was arrested a day earlier, has a criminal record dating back nearly a decade, and served about five years in prison for robbery, federal officials said.

In at least two capitals — Turkey’s Ankara and Belgium’s Brussels — officials also said they had disrupted plots to strike at New Year’s celebrations that stretch into Friday.

Turkish authorities said their festivities would go ahead as planned, despite detaining two suspected Islamic State militants believed to be planning suicide bombings. But Brussels Mayor Yvan Mayeur announced that the city had decided to cancel its fireworks celebrations due to a continuing threat.

Hours later, police carried out sweeps across the Belgian capital and a suburb. The operation was an apparent follow-up after two suspects were arrested Tuesday in connection with an alleged plan to carry out bombings during the year-end festivities. At least six additional suspects were taken into custody, police said, also noting that computers and mobile phones were seized.

[Authorities claim plots foiled in Turkey, Belgium]

Officials gave no other immediate details on the latest suspects, but the two arrested earlier in the week were part of a motorbike group known as the Kamikaze Riders, whose members are mostly of North African origin and carry out stunts.

Belgium has been on its highest alert level since the Nov. 13 Paris attacks, whose presumed mastermind, Abdelhamid Abaaoud, was Belgian and was raised in the hardscrabble Molenbeek district of Brussels.

A fireworks show also was called off in Paris, though there will be a video display at the Arc de Triomphe that Mayor Anne Hidalgo said would send a message: “Paris is standing, proud of its lifestyle and living together.”

Fireworks displays were due to go ahead in other European cities, but with a much heavier security presence than usual. Vienna police had said that several European cities had been warned of a possible New Year’s Eve attack, and that revelers in the Austrian capital would face tighter checks.

Thousands of police were due to be deployed in central London, though Mayor Boris Johnson said revelers should not be deterred. “Get out there and soak up the best we have to offer,” he said.

[The Belgium links to the Paris rampage]

Authorities in Russia and China announced that high-profile gathering places — including Moscow’s Red Square — would be closed for the evening. In India, local news agencies reported a possible New Year’s Eve threat to the country’s parliament building.

The precautions reflected a world rattled by the November attacks in Paris, which left 130 people dead, as well as the December killing of 14 people at an office party in San Bernardino, Calif. The Paris attacks are believed to have been directed by the Islamic State, while the group has claimed it inspired the couple behind the California killings.

In New York, security on Thursday was expected to be at its highest levels since the terrorist attacks of Sept. 11, 2001. More than 5,000 officers will be on patrol around the city, including a large contingent of specially trained counterterrorism officers who were activated this year. The contingent, known as the critical response command, will be armed with long rifles such as M4 carbines — a first for the city’s New Year's Eve celebrations.

[U.S. military: Airstrike kills militant with ties to Paris attack]

"There will be a tremendous number of officers that you will see, there will be many officers you won't see," said New York Mayor Bill De Blasio at a press conference this week.

In addition to helicopter surveillance, traffic officers and canine units, officers would be sweeping New York sites with chemical and radiation detectors.

In Washington, officials said there would be additional police at popular gathering spots and on the Metro.

Hugh Carew, a spokesman for the Metropolitan Police Department, said there were “no, new credible threats to the District of Columbia.” But he noted that D.C. “is often mentioned in propaganda from those that wish to do harm.”

[Al-Qaeda overshadowed, but not gone]

A security emphasis will be placed on the system’s busiest stations and popular nightlife spots, including Dupont Circle, Woodley Park, U Street and Clarendon, said Metro spokesman Dan Stessel.

“All of those stations will have robust police coverage,” Stessel said.

In Pasadena, Calif,. the annual Rose Bowl Parade will have more than two dozen law enforcement agencies providing security for the 700,000 spectators expected to attend.

Indian news agencies reported that the country’s parliament and prime minister, Narendra Modi, could be targeted in New Year’s Eve attacks. Security was strengthened across the capital, New Delhi. The reports specifically cited a threat from the outlawed terrorist group Lashkar-e-Taiba.

[Islamic State’s creation: Part terrorist, part gangster]

Late Tuesday, Indian security forces evacuated large number of people from the capital’s malls and marketplaces, and conducted drills.

Chinese officials, meanwhile, decided not to go ahead with riverfront celebrations in Shanghai — but apparently for reasons of crowd management, not terrorism fears.

It’s the second year running that the festivities have been cancelled, and it comes after a stampede killed 36 people and injured 49 as 300,000 revelers gathered for a fireworks and laser display by the Huangpu River on the final day of 2013.

In Beijing, a New Year's Eve countdown was cancelled at the China Millennium Monument.

Meanwhile, the Place, a popular shopping mall with the biggest LED ceiling screen in Beijing, also announced that the mall will close at its usual business hour Thursday, with no New Year’s Eve celebration organized.

Because of limited space, the New Year’s Eve countdown ceremony in Beijing's Imperial Ancestral Temple was only be open to people with tickets, Legal Evening Daily reported, adding that Beijing citizens and tourists can watch the celebrations on TV or via live streaming on the Internet.

Gibbons-Neff and Murphy reported from Washington. Simon Denyer in Beijing, Rama Lakshmi in New Delhi, Karla Adam in London, Andrew Roth in Moscow and Faiz Siddiqui contributed to this report.