Turkish police on Wednesday detained two Islamic State suspects accused of plotting a suicide bombing on New Year's Eve celebrations in the capital Ankara.

Ankara (AFP) - Brussels cancelled New Year's Eve celebrations due to terrorism fears as Europe prepared to see in 2016 under tight security, while in Turkey police detained two Islamic State suspects over a plot to attack Ankara.

Belgian authorities said a firework display and festivities to welcome the New Year that drew 100,000 people last year would not go ahead after revealing an alleged jihadist plan to attack the capital during the holiday.

The decision came the day after two people were arrested on suspicion of preparing attacks on "emblematic sites" in Brussels during the celebrations, and after another man was questioned over links to last month's Paris attacks.

"Unfortunately we have been forced to cancel the fireworks and all that was planned for tomorrow (Thursday) evening," mayor Yvan Mayeur told Belgian broadcaster RTBF. "It's better not to take any risks."

In Paris, where 130 people were killed by Islamists on November 13, the annual fireworks display on the Champs-Elysees has been called off and 11,000 police, soldiers and firefighters will patrol the French capital.

Moscow's Red Square, traditionally a place where people gather to ring in the New Year, will be closed to revellers on December 31 while Vienna has also beefed up security ahead of the celebrations.

In Turkey, meanwhile, officials said two Islamic State suspects, reportedly both Turks, were planning to stage suicide bombings in the centre of the capital Ankara, which is expected to be packed with revellers on the night of December 31.

Turkey has been on a high security alert since October, when two suicide bombers blew themselves up in a crowd of peace activists in Ankara, killing 103 people in the worst attack in the country's modern history.

- Ankara attack plot -

According to the private NTV television, counter-terrorism police arrested the pair in the Mamak district on the outskirts of the capital, which is home to more than five million people.

"They are suspected of being affiliated with the Islamic State and were planning an attack on the New Year in Ankara," a Turkish official told AFP, asking not to be named.

The two were planning to stage an attack in Ankara's main Kizilay square, the Anatolia news agency reported, citing the prosecutor's office.

The governor's office said the suspects, identified as M.C. and A.Y., had planned to strike two spots in Kizilay -- one outside a big shopping mall and the second in a street packed with pubs.

Police also confiscated one suicide bomb vest, one bomb mechanism with ball bearings and one rucksack with bomb-making materials, the governor's office said.

The alleged plot comes after a clampdown by police on suspected Islamists, including this month's arrest of an alleged member of the IS group suspected of planning a suicide attack on the US consulate in Istanbul.

In Turkey's biggest city Istanbul, 15,000 police will be deployed to ensure security over the New Year, the city's deputy police security chief Zafer Baybaba said.

- Global jihadist threat -

The security clampdown comes at a time of heightened fears about the global jihadist threat after a wave of attacks around the world, many claimed by supporters of the Islamic State group.

In New York City, where one million people pack into Times Square every year, officials said that 6,000 officers, some plainclothes, would be on hand to watch over celebrations.

Mayor Bill de Blasio on Tuesday said the security measures this year would be "more extensive than ever" and include more than 500 police trained in preventing terror attacks.

"We'll have a huge number of police out on New Year's Eve, including a lot of our new anti-terror force, the Critical Response Command," he said.

In Muslim majority Somalia, often targeted by Islamists, the government has banned celebrations of Christmas and New Year for fear of attacks.

Europe has been particularly fearful of being targeted by jihadists that have snuck in as part of a wave of refugees fleeing war in the Middle East, particularly strife-torn Syria.

In Germany, which has welcomed one million refugees this year, many shelters have also banned firecrackers and pyrotechnics to protect asylum seekers from reliving the trauma of wars they fled.