At least four people are dead and five injured after a fire in an e-bike repair shop in lower Manhattan early Tuesday, authorities said. 

Two of the injured were reported in critical condition and one of those who died was a 71-year-old man, officials noted.

FDNY Deputy Assistant Chief John Sarrocco told reporters firefighters responding to a 12:15 a.m. call found flames in HQ Ebike Repair on the first floor of the six-story building and put them out, but heavy smoke spread through the rest of the structure. That, he said, is where seven of the injured were found.

Six were initially listed in critical condition, fire officials said. The seventh suffered minor injuries, as did a firefighter and an EMT.

Police said four of the injured later died, including the 71-year-old man. One of the others whose life was lost was a man and the other two were women.

The blaze’s cause is under investigation.

The lithium-ion batteries that power e-bikes and e-scooters catch fire “with some regularity — and the numbers are rising,” The Washington Post quotes the National Fire Protection Association as saying. The association also says the batteries are known to cause explosions. And smoke from the batteries can also be toxic, experts say.