A Bengal tiger licks a glass enclosure during a presentation of Bengial tiger cubs at the Malabon Zoo in Malabon City, north of Manila, Philippines, 14 July 2016. The Bengal tiger cubs, which were born at the zoo, are two months old and named “Tiger Duterte” and “Tiger Leni”. The Malabon Zoo has one of the largest private collections of exotic and endemic animals in the Philippines. (Photo by Mark R. Cristino/EPA)

Members of the New People's Army (NPA) female guerrillas perform a cultural show during the release of a Philippines army soldier in Sugbongcogon town, Misamis Oriental, southern Philippines, November 20, 2015. NPA spokesperson Allan Juanito warned that they will seize more soldiers to exchange them with the government as "Prisoners of war". (Photo by Froilan Gallardo/Reuters)

A Philippine boy collects used plastic bottles to be sold at a junk shop at Divisoria market in Manila on November 29, 2017. (Photo by Noel Celis/AFP Photo)

A tourist stands on a paddle boat near soldiers taking part on a military and police drill in preparation for the temporary closure of the holiday island Boracay in Philippines on April 24, 2018. (Photo by Erik De Castro/Reuters)

A worker carries a bag of peeled carrots on her head outside a vegetable market in La Trinidad, Benguet in northern Philippines August 6, 2016. (Photo by Erik De Castro/Reuters)

Residents ride on top of an overcrowded “Jeepney”, a locally manufactured public transport, along a highway in Mogpog town on Marinduque island in central Philippines April 8, 2015. (Photo by Erik De Castro/Reuters)

Budgies feed on seeds from a local visitor's hands at Ocean Park in metro Manila, Philippines September 10, 2016. (Photo by Romeo Ranoco/Reuters)

Filipino Muslims ride on top of a vehicle as they celebrate the end of the holy month of Ramadan in Cotabato city, in southern Philippines, July 16, 2015. Picture taken July 16, 2015. (Photo by Marconi Navales/Reuters)