Metro Manila (CNN Philippines, March 5) — The Armed Forces of the Philippines is validating information that about 2,000 to 3,000 Chinese soldiers are in the country, calling it a "matter of serious concern."

"I have my staff for intelligence to confirm said reports in coordination with other relevant agencies of government," Gen. Felimon Santos Jr., AFP chief of staff, said in a statement.

Senator Panfilo "Ping" Lacson, a former national police chief, earlier disclosed that a reliable source told him about the presence of up to 3,000 members of the Chinese People’s Liberation Army. The source said the foreign troops seem to be "on an immersion mission."

Lacson called on intelligence authorities to "exert exra effort to gather information" on the matter.

Foreign Affairs Secretary Tedoro "Teddy Boy" Locsin shared an article citing Lacson's claims on Twitter. It got a rare response from the official Twitter account of the Chinese Embassy in Manila.

"Is the Senator testing the intelligence of the Philippine people?" the Chinese Embassy said.

Malacañang refused to comment until the information is confirmed.

Under the Constitution, foreign troops are not allowed in the country "except under a treaty duly concurred in by the Senate." The Philippines has exisiting forces agreements with Japan and Australia, but is abrogating its two-decade old military pact with the US.

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Lacson said officials "have every reason to be concerned" about the presence of Chinese troops in the country amid Manila's long-standing dispute with Beijing over the South China Sea. China claims almost the entire global waterway, including areas the Philippines claims and occupies as the West Philippine Sea.

Chinese nationals have also been sneaking in foreign currencies into the country, an issue that is now being investigated by the Senate Blue Ribbon Committee.