WASHINGTON -- Dozens of Activists held a rally here on Thursday to protest against the Guantanamo Bay detention camp while urging an end to "indefinite detention."

At Lafayette Square in front of the White House, some protesters were wearing orange jumpsuits and bags over their heads as others were holding banners that carry slogans urging the closure of the prison and an end to indefinite detention.

Their protests marked the 16th anniversary of the first prisoners arriving at the US facility, set up on the Guantanamo Bay Naval Base in southeast Cuba in 2002 as part of the US war on terror.

Former President Barack Obama tried to close the facility, but thwarted by Congress. Forty-one prisoners remain in detention.

Late last month, US Defense Secretary James Mattis visited the Guantanamo Bay Naval Base to meet troops, but he did not tour the detention camp.

It was the first trip to the base by a sitting Pentagon chief in almost 16 years since Donald Rumsfeld visited Guantanamo in early 2002.