(Reuters) -A barge crashed into a bridge on the Texas coast on Wednesday, forcing the closure of the only roadway to a small island off the city of Galveston, city officials said.

No injuries were reported and the Pelican Island Bridge remained standing after the barge, which Galveston County's Office of Emergency Management said was owned by Martin Petroleum, ran into it around 10 a.m.

The Office of Emergency Management said in a statement that "vacuum gas oil from the barge has been visually confirmed in the water" and that the barge's total capacity was 30,000 gallons. The amount that has leaked was unknown.

Calls to a number listed for Martin Petroleum Corp were not returned.

The Office of Emergency Management said that about 6.5 miles of the Intracoastal Waterway has been closed to water traffic.

TV images showed a portion of a railway that runs alongside the bridge, located about 60 miles southeast of Houston, collapsed atop the barge.

The City of Galveston said in a written statement that "the U.S. Coast Guard is responding and will determine the extent of the spill, as well as initiate the containment and cleanup processes."

An investigation is underway, the statement said. Officials have not yet said what may have caused the accident.

The Coast Guard did not respond to requests for details.

Engineers from the Texas Department of Transportation were en route to examine the bridge, which will remain closed until it is deemed safe, the city said.

The collision comes amid heightened concerns in the U.S. about the vulnerability of bridges to large ships, after a cargo ship collided with Baltimore's Francis Scott Key Bridge in March, killing six people and leading to the collapse of the structure.

(Reporting by Brad Brooks in Longmont, Colorado, and Rahul Paswan in Bengaluru; Editing by Leslie Adler and David Gregorio)