Heavy snow and strong winds slammed the northeastern United States on Sunday, cancelling hundreds of flights and causing travel chaos.

The US National Weather Service issued blizzard warnings along the coast from Maine down to New Jersey with winter storm warnings in effect for nearly the entire East Coast.

The weather service forecast 15 to 25 inches (38 to 64 cm) of snowfall in New York City through Sunday night with widespread blowing of snow expected on Monday, when many people will be returning to work after celebrating Christmas.

Hundreds of flights were cancelled at area airports and Amtrak cancelled passenger rail service between New York and Boston.

A snow emergency was in place in Boston, meaning only essential employees are being asked to work on Monday.

At least four airlines -- United Continental Holdings' United Airlines and Continental, Delta Air Lines and American Airlines -- said on their websites they were granting waivers and rescheduling rights for people travelling through northeastern US airports this weekend.