The unmanned United States drone discovered by fishermen off the waters of Masbate province was not part of any joint exercises between American and Philippine military forces, the US Embassy in Manila said on Tuesday.

The American embassy said that the drone, an expanded BQM-74E Aerial Target, was launched from the USS Chafee (DDG 90), during the Valiant Shield 2012 exercise in Guam on September 19, 2012.

“It appears that ocean currents brought the drone to where it washed ashore last week off Masbate Island,” the embassy said.

On Sunday, Masbate fishermen discovered the drone, which the embassy said was unarmed and unmanned.

The Armed Forces of the Philippines also confirmed on Tuesday that the drone that was recovered off Ticao Island in Masbate was not a spy or surveillance-type plane nor was used in military operations.

Col. Arnulfo Marcelo Burgos Jr., military spokesman, said that the Philippines and US navies did not used drones during joint military exercises.

The Senate committee on foreign relations demanded an explanation from the Visiting Forces Agreement Commission (VFA).

Sen. Loren Legarda, chairman of the committee, said that the recovery of the drone raises serious concern on national security and the VFA commission should submit a through report to the committee.

The department of Foreign Affairs, however, said that the Philippine government has been assured by the US Embassy that the aerial vehicle “is by design and purpose, solely used for target practice and not armed or used for surveillance.”

“The presence and activities of US military personnel in the Philippines is governed by the VFA between the Philippines and the US. This matter will be dealt with in accordance with the treaty obligations contained in this agreement,” Raul Hernandez, Foreign Affairs spokesman, said.

US drones are allowed to make reconnaissance flights on Philippine aerial territory, but they are not allowed to make strikes.

The VFA that was entered into by Manila and Washington also allows US troops to train their Filipino counterparts in various military activities, especially pertaining to antiterrorism campaigns.

Bernice Camille V. Bauzon , William B. Depasupil, Jefferson Antiporda and Rhaydz B. Barcia