[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/05/14/art.chelsea.hillary.clinton.jpg caption="Chelsea Clinton has been campaigning for her mom in Puerto Rico since Tuesday."]
WASHINGTON (CNN) - The U.S. Navy denied Chelsea Clinton access to a former firing range in Puerto Rico on Wednesday, Navy officials said.
The Navy rejected the request because U.S. law forbids campaigning on federal property and because the Navy allows only people clearing the Vieques range of ordinance to enter the area, the officials said. They said they did not know what Clinton planned to do there.
The U.S. Navy used the long-controversial Vieques range - the majority of the island of Vieques - for bombing and artillery practice until May of 2003. It was the target of frequent protests by Puerto Ricans who objected to its use. It is now federal property being cleaned of unexploded ordnance.
Clinton - who has been campaigning for her mother, Democratic presidential candidate Hillary Clinton - is in the U.S. territory ahead of its June 1 primary. It is the largest prize left for the Democratic candidates.
Barack Obama's wife, Michelle, is also due to campaign there.