Terror threats have provided a sobering backdrop to New Year's Eve events planned around the world, reports CNN.
Here in the U.S. security officials at federal and local levels are increasing security around high-profile events while officials in other countries do much of the same.
Here's what's going on around the world.
Before he left for vacation for Hawaii, security officials briefed President Barack Obama about an uncorroborated threat based on a single source that didn't mention specific locations or cities.
They did, however, say they were concerned about "soft targets" or public spaces with lots of people. In the wake of attacks such as the San Bernardino shooting in California, the FBI is increasing staff in command centers around the country.
The major of Brussels says there will be no New Year's festivities in the capital city, not even fireworks.
Belgian authorities arrested two people on suspicion of plotting an attack, authorities announced Tuesday.
An anonymous official said that members of a Muslim biker gang had discussed perpetrating ann attack. Its status is unknown at this time.
Turkish police announced that they've arrested two people with alleged ties to ISIS on suspicion of planning a New Year's Eve attack. The pair were in possession of explosives and shrapnel.
Investigators believe the two were planning to target two locations near Ankara's Kizilay district.
Austrian officials are on high-alert after several European cities were warned of possible terror threats. Vienna police received the names of possible attackers and are investigating.
The main New Year's Eve event in Austria is the Hofburg Silver Ball. There are also other large outdoor even in front of Vienna's city hall.
WATCH | The Hofburg Silver Ball New Year's Eve celebration
Authorities in Shanghai announced that there will be no celebrations on the Bund, a popular riverfront ahead.
The announcement seems to have been prompted by the stampede that killed 36 people and injured 49 more on New Years Eve in 2015.
Those who do go to the riverfront will have to comply with public order rules.
And in cyber space, pro-ISIS accounts on social media are advocating for attacks online.