BEIJING -- Irresponsible actions by some countries have escalated South China Sea disputes, challenging the post-war international order, according to a think tank report issued Thursday.

The report, titled "Historical and Legal Basis of China's Territorial Sovereignty and Maritime Rights in the South China Sea," was released by Xinhua Institute, a think tank affiliated with Xinhua News Agency.

According to the report, since 2020, the Philippines, emboldened and supported by non-regional powers, has confronted China's efforts to protect legitimate and lawful rights in the South China Sea through its "gray zone" strategy.

"Irresponsible actions by countries like the Philippines have escalated South China Sea disputes to a level close to 'quasi-military operations,' even pushing the situation to the brink of conflict or war," it says.

This report is part of a series of three reports on the South China Sea issue released by Xinhua Institute. The other two reports are titled "Incitement, Threats, and Lies -- The Truth about External Forces Interfering in the South China Sea Issue," and "Making the South China Sea a Sea of Peace, Friendship and Cooperation: China's Actions."