New cases of African swine fever were detected in some areas in Cavite, south of the nation's capital Manila, and in Nueva Ecija on Luzon island.

Cavite Governor Jonvic Remulla confirmed the cases detected in two villages in his province and said a "lockdown" had been declared to contain the disease.

Agriculture Secretary William Dar also confirmed infections in Nueva Ecija, but said they were "limited".

The incurable disease, which can be spread via fomites and in uncooked pig products, continues to wreak havoc on hog industries in China and Southeast Asia.

The Philippines, the world's seventh-biggest pork importer, has further tightened its animal quarantine rules to protect its $5 billion hog industry, after declaring its first outbreak on 9 September and reporting several more cases since.

The infections, which are contained so far on the northern island of Luzon, have prompted the culling of more than 30,000 pigs so far in virus-hit areas.

To protect their industries, several provinces in central and southern Philippines have imposed a ban on pork and pork-based products from Metropolitan Manila and other virus-hit provinces.