LONDON -- One of London’s busiest parks was cordoned off Friday after an unexploded World War II mortar was discovered in a lake just yards from Kensington Palace.

Police responded to reports of a suspicious object in Hyde Park's Serpentine Lake, which was found to be an unexploded mortar round. The device poses no danger to the public and has been removed, authorities said.

"Police are dealing with reports of a possible unexploded ordnance device partially submerged in The Serpentine, W1," London’s Metropolitan Police said in a statement. "Specialist officers are attending and a cordon is currently in place between the Triangle car park and the boat house on Serpentine Road."

The Serpentine Lake in Hyde Park is a major tourist destination, located near a memorial to Princess Diana and the historic royal residency of Kensington Palace.

“We can confirm that a suspicious object, probably an unexploded WW2 bomb, has been found in the Serpentine Lake,” Royal Parks, the charity that manages Hyde Park, tweeted Friday morning. “Specialist police officers are on the scene and a cordon is currently in place between the Triangle car park and the boat house on Serpentine Road.”

The cordon has since been lifted and the park has reopened. Police at the scene told ABC News the device was about 12 feet long.

The United Kingdom was heavily bombed during World War II, so the discovery of unexploded bombs is a common occurrence. An estimated 10 percent of German bombs that hit the British Isles did not explode, according to Ministry of Defence data given to the BBC.

This is the second time this year a device of this nature has been discovered. In February, London City airport was closed down when a bomb was found in the nearby Thames River, according to the Associated Press.