LONDON (AP) — The World Health Organization says it has noticed mutations in the bird flu virus that is now spreading in China, but says the risk of the disease spreading easily between people still remains low.

In a press briefing Wednesday, the U.N. health agency said in about 7 percent of the people infected with the H7N9 strain of bird flu, scientists have identified genetic changes suggesting the viruses are resistant to Tamiflu, the recommended treatment for the disease. Wenqing Zhang, head of WHO's flu department, said the rate is similar to what has been picked up in previous years.

Zhang said mutations in the H7N9 virus have also made it more deadly to birds, but he says it's unclear what that might mean for humans.