MANILA – The Philippines has issued a diplomatic note to China seeking explanation on a South China Sea incident over suspected rocket debris, in a move that could further strain the nations’ ties.

The Philippines’ Department of Foreign Affairs wants China to clarify what happened between the South-east Asian nation’s Navy and the Chinese Coast Guard in waters off Pag-asa Island on Nov 20, the agency’s spokesman Teresita Daza said on Thursday.

A Chinese vessel “forcefully retrieved” suspected rocket debris being towed by the Philippine Navy in the South China Sea, the Philippine Daily Inquirer reported, citing the military. China has denied any interception or seizure, according to CNN.

The latest incident presents another challenge to the Philippines’ ties with China.

Philippine President Ferdinand Marcos Jr has recently been fostering his nation’s longstanding alliance with the United States.

He is also seeking compromise with China over a maritime and territorial dispute in the South China Sea, including on oil exploration. BLOOMBERG