Thousands of people could be at risk from a deadly virus in a United States national park that has already claimed two lives, officials say.
The Centers for Disease Control and Prevention (CDC) said about 10,000 visitors who stayed at a Yosemite National Park campsite in California between June and August could be at risk of contracting the virus.
The outbreak of the Hantavirus, a rare lung disease, is thought to have been caused by mice nesting in the insulation of tents at a campsite in the Curry Village area of the reserve, the BBC reports.
The first death was reported earlier this month. One of those who died was a 37-year-old man from the San Francisco Bay area. Four other cases have been reported.
There is no known cure for the virus, spread by infected rodent droppings. Severe cases can lead to extreme breathing difficulty and death and one third of cases are fatal.
The disease can also spread if people touch or eat contaminated substances, or are bitten by an infected animal.
Park officials closed all 91 "signature" cabins after finding deer mice, which carry the virus, nesting between the double walls of the luxury tents.
Nearly four million people visit Yosemite National Park annually and about 70% of them visit Yosemite Valley, where Curry Village is located.
The park has seen two other cases of Hantavirus in a more remote area in 2000 and 2010, but this year's deaths were the first.