The area is located on the edge of the Tibetan Plateau in northern Sichuan province, home to many Tibetan and other ethnic minority villages.
A man surnamed Song who answered the phone at a local emergency office in Aba prefecture, where the Jiuzhaigou national park is located, said the nearby town of Zhangzha reported the deaths and injuries. Song did not say where the five tourists who died were from.
Earthquakes are common in China's west, although the low population density there often means casualties are low. China's deadliest earthquake this century, a magnitude-7.9 temblor with a depth of 19 kilometers (12 miles), struck Sichuan province in May 2008, killing nearly 90,000 people.
The epicenter in Tuesday's quake was about 39 kilometers (24 miles) from the county of Jiuzhaigou, which has a population of around 80,000, in an area that's 2,000 meters (6,562 feet) above sea level. It was 285 kilometers (177 miles) from Chengdu, the densely populated capital of Sichuan province, according to the Chinese center.
The Xinhua News Agency said strong tremors could be felt in Chengdu. The Sichuan provincial government's news website said that after the quake struck, a number of train services to Chengdu and other cities were suspended.
Jiuzhaigou county had a massive power outage following the quake, Song said. Local officials were being sent to the town of Zhangzha, which was closest to the quake's epicenter.
"The tremors were very strong," said a woman in Jiuzhaigou town who gave only her surname, Wang, and said she worked for a travel company. She said the damage in the town center seemed minimal other than the suspension of electricity.
"People from other regions are a pretty frightened," Wang said.
Yu Qian, a local taxation bureau official, told Xinhua that she felt strong shaking that sent her and her two children rushing from their home on the fifth floor. Yu said the quake cut off power in her neighborhood and disrupted telephone service.
"I was getting into a car at the time of the quake, and it felt like a heavy-duty truck roaring past," said Liu Yanrong, a local township official, told Xinhua.
Xinhua cited a worker at the Jiuzhaigou park named Sangey as saying that some houses in the tourist site collapsed or cracked following the quake and that authorities were organizing evacuations of residents.
Images on Chinese social media sites showed rocks scattered on roads and people running out of bars and cafes in Jiuzhaigou town onto the street.
A report on the news site's official microblog also cited Zhao Wei, the party secretary of the Communist Youth League's Jiuzhaigou division, as saying some telephone communications networks were down, making it difficult to determine the scale of the damage.
The China Earthquake Networks Center said the quake was followed about 20 minutes later by a temblor measuring 3.3 in magnitude at a depth of 9 kilometers (5.5 miles).