MANILA — Sen. Imee Marcos on Sunday questioned the presence of "yet more" military planes of the United States Air Force in Manila and Palawan, a week after a similar aircraft was sighted at the Ninoy Aquino International Airport (NAIA).

In a statement, Marcos said that a US Air Force C-17 military transport plane landed in Manila at around 6:03 a.m. Friday from the Andersen Air Force Base in Guam, which later flew to Palawan before heading to the Yokota Air Base in Fussa, Japan in the afternoon.

Citing flight tracker FlightRadar24, the senator said the plane left Palawan at 4 p.m. Manila time and arrived at the Yokota Air Base at at around 9:30 Japan time.

"The flight route from Palawan showed the plane passing over Pampanga, Cagayan, and off the eastern coasts of Batanes and Taiwan before it landed at the Yokota Air Base," Marcos' statement read.

Another American C-17 plane from Tokyo was also spotted north of Busuanga, Palawan past 10 a.m. Saturday. It disappeared on radar until it was again located flying over Polillo Island before exiting the Philippine territory at around 6 p.m.

"Too little is known about ongoing US military activity in our territory while we constantly call out the presence of Chinese vessels in the South China Sea," Marcos said.

"I am aware of ongoing exercises with foreign militaries this month. But the same zeal in tracking any violations in our maritime territory and EEZ (exclusive economic zone) must also apply where Philippine air traffic rules and joint military agreements with the US are concerned," she added.

The senator also called on Philippine military, defense, and foreign affairs officials to determine if these US military flights affected ongoing tensions in the South China Sea and Taiwan Strait.

US military aircraft were first spotted in the Philippines on June 26, after a C-17 aircraft landed in NAIA at 8:08 a.m. that day.

• Imee calls for probe on NAIA landing of US Air Force plane

The Senate Committee on Foreign Relations, which Marcos chairs, earlier released a statement noting that the incident was a result American flight planners failing to coordinate beforehand with NAIA ground handlers.

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