Qantas has banned alcohol, perfumes and other liquids bought at airport duty-free shops in Manila and is doing its own bag searches over concerns Islamic State militants may carry out an airborne terror attack, according to News Corp.

The move follows an insurgency in the Philippines by foreign-led jihadists who since May 23 have occupied the city of Marawi in the country's south.

Qantas has conducted a security review at Manila and begun its own mandatory searches of passengers' carry-on bags at the Manila departure boarding gate, News Corp reported.

It says the airline has banned the purchase of liquids including alcohol and perfume and bottles of water over 100ml purchased at airside duty free shops as an added precaution.

This is on top of the usual 100ml liquid limits in hand luggage.

AAP