Four people have died and several are missing after a gas leak sparked an explosion which levelled two buildings in New York City, authorities say.

Scores of others have been injured in the incident, which sent smoke billowing into the city sky.

Rescue crews began searching the debris on Wednesday evening for victims after the fire was finally put out.

Train services to and from Grand Central Terminal have been restored after a complete halt earlier.

The area is engulfed in thick choking smoke, says the BBC's Nick Bryant at the scene