China Coast Guard said on Thursday that it had taken lawful and professional measures to safeguard a Chinese scientific research vessel conducting a marine ecological survey near Houteng reef in the South China Sea.

According to Jiang Lue, spokesperson for the China Coast Guard, the Chinese research ship?Xiangyanghong 33 was carrying out a routine ecological and environmental survey in waters near the reef on Wednesday when a Philippine Coast Guard aircraft deliberately approached and disrupted the operation.

Jiang said the China Coast Guard conducted tracking, monitoring and control measures in accordance with laws and regulations to ensure the safety of the Chinese vessel and its operations."

The entire operation was carried out in a professional and standard manner," he said.

The spokesperson accused the Philippine side of "distorting facts and confusing public opinion" through its remarks on the incident, urging Manila to immediately stop what he described as illegal interference and smear campaigns.

Jiang added that the China Coast Guard will continue to carry out rights protection and law enforcement activities in waters under China's jurisdiction in accordance with the law, and will take all necessary measures to safeguard the safety of Chinese scientific research operations and maintain peace and stability in the South China Sea.