Police were probing a firebombing on a West Village smoke shop after unknown objects were hurled through the window and exploded early Wednesday, authorities said.

Roughly six suspects were spotted tossing the object after breaking the window of the Christopher Street shopfront just after 3 a.m., cops said.

FDNY crews responded to the scene following reports that a fire had broken out inside the building, which also houses a barber shop.

The bomb squad was also on the scene early Wednesday as police investigated whether it was arson.

A video obtained by The Post showed two suspects lobbing two objects through the storefront window. The first suspect approached with a bottle that was already ablaze, according to the video. 

The second suspect lit what sources said appeared to be a high-powered “M-80” type firework and quickly chucked it at the store. 

The two objects combined created an inferno that briefly blinded out the surveillance cameras while the suspects staggered away.

Flames were seen shooting upwards almost like a geyser while the suspected firework continued to fizzle. 

Interior surveillance footage showed smoke filling the store while the fire burned near the window. Some items typically sold at smoke shops, including e-cigarette juice, are highly flammable. 

Sources told The Post that they believe the first object chucked at the shop was a Molotov cocktail, based on a glass paper towel that was found at the scene.

M-80 fireworks have been banned under Federal Law since 1966 “because of the large amounts of explosive composition they contain,” according to the American Pyrotechnics Association.

It’s unclear what the other incendiary objects thrown at the store may have been.

Alarmed residents told The Post they were woken up by a “big boom” — and feared a bomb had gone off.

“My initial thought was that it was a bomb,” said Jamon Exsted, who has lived in the West Village for 20 years.

“I was, like, we are in the West Village … like what’s really around here? It didn’t feel like there is something to target in this neighborhood.”

“I thought it was like lightning because, you know, we had a storm earlier in the day. But I looked out, and there were no signs of a storm so immediately I thought it was like something suspicious,” Max Giuliani, who grew up in the neighborhood, added.

“I got a bunch of my neighbors saying, ‘What was that? What was that?’ It was an explosion I’ve never heard before. It really rattled the neighborhood.”  

The fire marshal was working to determine the cause of the blaze, police said.

The suspects were spotted running away. Their descriptions were not immediately released.