No traces of explosive have been found from the samples of the debris of MU5735 so far, head of the Guangxi Fire and Rescue Brigade said, on Saturday.

"After examining 41 of the 66 samples of the debris sent to the laboratory, no traces of common organic and inorganic explosives have been found," Zheng Xi, head of the Guangxi Fire and Rescue Brigade, said at a news conference in Wuzhou, Guangxi Zhuang autonomous region.

Rescuers have so far found no survivors. The cockpit voice recorder was found on Wednesday near the point of impact, and it was sent to a laboratory in Beijing for decoding and analysis.

Zhu Tao, head of the aviation safety office of the Civil Aviation Administration of China, said on Saturday that although the second black box—flight data recorder—from the aircraft still hasn't been recovered, an Emergency Locater Transmitter located near the FDA has been found.

"More than 24,000 pieces of the aircraft debris have been found. A warehouse to store them has been set up so they can be categorized for analysis," he said.

Zheng said rescuers are still making their utmost efforts to look for signs of lives and the second black box. "We'll not give up any hope," he said, adding that more firefighters have arrived at the scene from other cities in Guangxi to help with the rescue work.

China Eastern Flight MU5735 left Kunming, the capital of Yunnan province, at 1:11 pm Monday with 123 passengers and nine crew members onboard. It was scheduled to arrive in Guangzhou, Guangdong province, at 3:05 pm. Air traffic controllers lost track of the plane over Wuzhou at 2:21 pm.