Two people were wounded in a shooting at the U.S. Holocaust Memorial Museum in downtown Washington D.C. on Wednesday, local police said.

The D.C. Police Department said a man walked to the museum and shot a security guard, according to local TV reports. Another guard returned fire and shot the suspect.

Both of the wounded were sent to hospital with serious injuries, and their conditions remain unknown.

The D.C. Fire Department said another person was also injured from broken glasses at the museum.

The shooting was reported to police at 12:52 p.m. local time (1652 GMT) and officers rushed to the scene just south of the Independence Avenue bordering the National Mall, not far from the White House.

Eyewitnesses told local TV that the gunman carried a "long gun," probably a rifle or a shotgun.

Roads surrounding the museum have been closed off as emergency vehicles and police cars converged on the scene.

The museum is a popular tourist site in the U.S. capital, with 1.7 million visitors each year.

It has a heavy security presence and imposes security check methods.

It is not clear whether the gunman went through the metal detector or not.

Schoolgirl Abigail Perkins was on a school trip to the museum at the time. She said she and fellow students heard several gunshots before they were told to leave the building.

Dave Pearson, a teacher in Washington, said he was on the museum's fourth floor when he heard a loud noise.

"At the time, we're visiting and all of a sudden there's like a boom, and all of a sudden they told us to stop where we're at. The only thing we heard was a boom, and that was it."

Source: Xinhua