Gunman James J. Lee. (AP)

New York, Sept. 2: Police officers shot and killed a gunman with a history of protesting against the Discovery Channel, the authorities said, ending a nearly four-hour ordeal yesterday at the company’s headquarters in Silver Spring, Maryland.

The gunman, apparently wearing explosives, had taken two employees and a security guard hostage, officials said. The hostages, all men, were unharmed.

The police negotiated by phone throughout the afternoon with the gunman, who was on the first floor, as the rest of the 1,900 employees and the children in the day care center were leaving the building.

At 4:48pm (local time), believing the hostages were in danger, the police shot the gunman, Chief J. Thomas Manger of the Montgomery county police said at a news conference.

Chief Manger said it had been reported that the man pulled out a handgun and pointed it at one of the hostages.

“At that point,” he said, “our tactical units moved in. They shot the suspect. The suspect is deceased.”

Police officials said the company had identified the gunman to them as James J. Lee. A website run by Lee, SaveThePlanetProtest.com, was established in January 2008. The website complains that the Discovery Channel produces programmes about the environment for profit, not for humanitarian reasons.

Discovery Communications operates the Discovery Channel, Animal Planet, TLC and a number of other cable channels.

The Montgomery county state’s attorney said Lee was arrested in February 2008 and later convicted of disorderly conduct after a protest outside the Discovery Channel. Without using Lee’s name, Chief Manger said the gunman yesterday was the same person who was arrested in 2008.

A spokesman for the Discovery Channel, David Leavy, said Lee had thrown $20,000 into the air at the protest, where a crowd of people rushed to grab it.

The state’s attorney said that as a condition of Lee’s probation, which ended two weeks ago, he was barred from going within 500 feet of the Discovery headquarters.

The authorities said the gunman entered the Discovery building around 1pm yesterday, bringing one of Washington’s largest and busiest suburbs to a standstill for hours.