OCRACOKE, N.C. — Authorities say a fireworks explosion on a North Carolina island only reachable by ferry has injured several people.

Hyde County spokeswoman Jamie Tunnel says she isn't sure how many people were hurt or how badly they were injured after a truck carrying fireworks exploded Saturday on the Ocracoke Island docks.

The island holds a fireworks celebration each Independence Day.

Anchorage Marina dock master Robert Raborn says the explosion was heard across Ocracoke village. He watched numerous medical helicopters fly in.

Raborn says from his vantage point 200 yards away, it looked like 40 minutes worth of fireworks went off in four seconds.

Ocracoke Island is the southernmost inhabited island on the Outer Banks, about two hours from the mainland, and is only accessible by ferry.