A 6.1-magnitude earthquake in Ya'an, a city in southwest China's Sichuan Province, has killed four and injured 14 others as of 7.40 pm on Wednesday, and rescuers are scrambling to find those who have been trapped, China Central Television CCTV reported.

People who were injured in the earthquake are being treated in hospitals in Ya'an, media reports said, citing Ya'an Municipal Health Commission.

Giant pandas and staff at the Ya'an base of the China Conservation and Research Center for the Giant Panda are safe, read a statement issued by the center on its official Weibo account in response to netizens' concerns.

The earthquake shook Lushan County in Ya'an, Southwest China's Sichuan Province, at 5 pm on Wednesday, according to the China Earthquake Networks Center (CENC).

The epicenter, with a depth of 17 km, was monitored at 30.37 degrees north latitude and 102.94 degrees east longitude, the CENC reported.

Strong tremors were also felt as far away as Sichuan's provincial capital of Chengdu and Chongqing Municipality, netizens said on Sina Weibo.

The Sichuan fire department said some houses in Lushan County were partially damaged, and it's continuing to communicate with relevant counties and towns that have been affected.

Over 1,400 firefighters from the rescue team in Sichuan Province have rushed to help. Meanwhile, rescue teams from Southwest China's Guizhou and Yunnan Provinces and Chongqing Municipality are ready as reinforcements if necessary.

A school teacher who lives in Xinjin district of Chengdu, about 100 kilometers from the epicenter, told the Global Times that he felt the tremor very strongly at his school.

"I was in a classroom on the fourth floor of a school building, and the level of shaking I felt was several times that of the magnitude-3.0 or -4.0 quakes that have occurred recently," the teacher, surnamed Jiu, said.

"The students were rather scared because one wave of quakes ended and then another round came," he said. "Two such consecutive earthquakes and the intervening horizontal waves have hardly been experienced before."

"I felt the tremors were similar to the 2008 Wenchuan earthquake," Jiu said. "But this time everyone was more experienced and ran to a calmer area before observing and contacting their families."

Especially after the last few earthquakes, local residents have become much more frequent and motivated to conduct earthquake drills, he said.

Companies in some of Chengdu's higher-floor office buildings suspended their offices after the quake. Some high-speed rail lines in Sichuan were also temporarily suspended, residents said.

A resident surnamed Pang in Meishan City, about 120 kilometers from Ya'an, told the Global Times that he barely felt the tremor, which was felt only slightly in high-rise buildings there.

"My friends in Ya'an told me that they held an earthquake drill yesterday in Tsai, so everyone is more relaxed about the quake," Pang said.

A tour guide working in and around Ya'an said that after a check, the roads and landscape inside Niubei Mountain, a famous local tourist attraction at 3,666 meters above sea level, were undamaged. As of 6 pm, the shuttle bus had resumed traffic and everything was normal at the lodging hotel at the top of the mountain.

Jiu, who had previously lived in Ya'an for a long time, told the Global Times that given the terrain and weather in Ya'an, a heavy rainfall after an earthquake could be more dangerous than the quake itself.

"Usually a medium earthquake can cause some geological loosening in the mountains of Ya'an, and with the summer weather, landslides can easily form," he said, worriedly.

The State Council's Earthquake Relief Headquarters Office and the Ministry of Emergency Management have activated a Level-III emergency response, and also sent a team of experts led by the deputy director of the China Earthquake Administration to the site for rescue and relief operations.

According to experts, the earthquake in Ya'an was an aftershock from the 7.0-magnitude earthquake that killed more than 100 people and injured thousands in 2013. The two quakes were centered 9 kilometers apart and were triggered by the Shuangshi-Dachuan fault zone.