Philippine security officials said Thursday they took into custody five more Chinese spies, following the arrest of a compatriot for espionage this month.

The arrests come as confrontations between the two Asian neighbours over contested reefs and waters in the strategic South China Sea have escalated in recent months

The Philippines said on Saturday it has suspended a scientific survey in the South China Sea after two of its fisheries vessels faced "harassment" and aggressive behaviour from China's coast guard and navy.

The South China Sea is a complex geopolitical issue involving territorial disputes, military tensions, and conflicting claims by littoral countries including China. Analysts say as the waterway is one of Beijing’s core interests, it is also listed as “highly sensitive” by censors.

An expert told Newsweek China is hostile due to frustration at the presence of the U.S. Typhon missile system in the Philippines.

One fictional student in the 40-page comic book describes China as a bully and another says Beijing's "behavior is outrageous."

The Philippines has launched a comic book to counter what the country says is China’s disinformation campaign to push its expansive territorial claims in the South China Sea.