BEIJING: China on Wednesday defended the alleged intrusion of 16 Chinese military aircraft into Malaysian airspace.

The incident happened on Monday when Malaysia's air force said its radar picked up the Chinese planes near Malaysian-administered islands in the disputed South China Sea.

In a briefing in Beijing on Wednesday, China's foreign ministry said it had been a routine training exercise and denied entering Malaysia's territorial airspace.

Foreign Ministry spokesperson Wang Wenbin insisted that the Chinese aircraft followed international law.

China claims almost the entire South China Sea on historic grounds. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have overlapping claims, and tensions have ramped up since China built several man-made islands and turned them into military outposts.

Commenting on the World Health Organization's decision to issue an emergency use listing for the COVID-19 vaccine made by Sinovac for adults 18 and over, Wang said it proved the "safety and efficacy" of Chinese vaccines.

It is the second such authorization WHO has granted to a Chinese company. WHO's authorization means the vaccine can be bought by donors and other UN agencies for use in poorer countries, including in the UN-backed initiative to distribute COVID-19 vaccines globally known as COVAX.

Separately, Wang again urged the US to open its Fort Detrick base for international investigation, amid repeated claims from

Chinese officials and state media that COVID-19 might have originated from an American military research laboratory.