The Chinese naval fleet docked in Hong Kong for a five-day port visit has welcomed two former anti-Japanese guerrilla fighters, as the veterans onboard a warship hailed the country's military advancement.

Lam Chun and Law King-fai, both in their 90s, made a trip to the Ngong Shuen Chau Barracks on Stonecutters Island and the destroyer Zhanjiang on Saturday.

They were once part of the Dongjiang Column, a guerrilla force fighting the Japanese during the Second World War.

"We have now witnessed the warships making concrete advances, defending our motherland," Lam said.

"They are not here to be involved in battles, but to protect ourselves, so that we can continue with our development."

Law, for his part, recalled going to war in wooden boats back in the day, saying the country's naval vessels and weapons have changed and developed rapidly throughout the years.

The Shandong aircraft carrier and other vessels in its strike group are in Hong Kong until Monday.