Admission to a giant panda research center in northern China has been suspended to protect the animals from swine flu, Xinhua news agency said on Tuesday.

Visits to the Shaanxi Wild Animal Rescue and Research Center, one of China's four giant panda bases, were halted last week after heavy snowfall brought sudden temperature drops and a rise in the number of A/H1N1 flu patients, Wang Gang, a zoo worker, told Xinhua.

"It's still not certain whether pandas are susceptible to A/H1N1 flu, but we need to be careful," the agency quoted the center's deputy director Jin Xuelin as saying.

Only five panda carers and two vets are currently allowed to enter the center, home to 21 giant pandas, including three cubs born this year.

According to Xinhua, the first swine flu death was reported in Shaanxi Province last Friday and at least 13 were critically ill with the epidemic as of Monday, the provincial health department said.

Jin expressed hope that the center would reopen to visitors after the flu season, "in spring."

A visit to the center, founded in 1987, costs 35 yuan ($5).

BEIJING, November 24 (RIA Novosti)