A human rights lawyer became the 34th attorney to be killed under the administration of President Rodrigo Duterte after being shot dead in the central Philippines, police and colleagues said Wednesday.

Landslides killed four people and trapped at least 31 others on Tuesday in a mountainous region of the Philippines, officials said, as Typhoon Yutu barrelled across the country with strong winds and rains.

Typhoon Yutu maintained its strength as it moved closer to the northern Philippines on Sunday, prompting authorities to warn of possible floods and landslides.

Philippine rights groups said on Wednesday they had begun investigating the killings of nine farmers who had occupied part of a sugar plantation, adding pressure on the government to better protect land activists.

Japanese troops stormed a beach in the Philippines Saturday in joint exercises with US and Filipino troops that officials said marked the first time Tokyo's armoured vehicles rolled on foreign soil since World War II.

At least 155 people have been killed in landslides and other accidents caused by Typhoon Mangkhut and monsoon rains in the Philippines, officials said Sunday.

Dozens were still missing as authorities probed whether a nearby rock quarry could have played a role in the massive hillside collapse on Thursday.

Singapore is home to almost 250,000 maids, mostly from poor parts of Indonesia or the Philippines.

The new tragedy comes just days after Typhoon Mangkhut pounded the nation's north with heavy winds and rain, sparking a separate landslide that left dozens dead.

Mangkhut swamped farm fields in the nation's agricultural north and smashed houses when it tore through at the weekend with violent winds and heavy rains.

The typhoon smashed homes and flooded key agricultural regions in the northern Philippines before battering Hong Kong and southern China with fierce winds and heavy rain.

The death toll in the Philippines, where the main island of Luzon was mauled with fierce winds and rain, rose to 65 overnight.