AFP, Tokyo

Tens of thousands of people were advised to evacuate on Friday as Japan was hit by heavy rains just two weeks after a deadly typhoon barrelled through the country.

The Japan Meteorological Agency issued warnings of heavy rains, landslides and floods in a swathe of areas including eastern and central Japan.

"We see extremely heavy rains in areas centring around Chiba prefecture," the JMA warned on its Twitter account, referring to a region east of Tokyo.

"As risks of disasters have already increased, please be extremely vigilant about landslides, rise in river water volumes and floods as rains will continue," it said.

Non-mandatory evacuation orders were issued to more than 4,000 residents in Chiba, and tens of thousands of others were also advised to evacuate in other prefectures, public broadcaster NHK reported.

Footage showed cars splashing through roads partly inundated with water, and swollen rivers seemingly on the verge of flooding.

The Chiba prefecture announced it planned to discharge water from dams that had reached maximum capacity later Friday, raising worries of river overflows in densely populated downstream areas.

Japan was hit by typhoon Hagibis about two weeks ago, with the death toll from the violent storm now standing at more than 80.

Residents still picking up the pieces after that storm expressed frustrations over reconstruction delays and their fear of another disaster.

"I'm a bit worried that if an evacuation order is issued, we will have to leave here," a woman in Nagano in central Japan who was cleaning up mud told NHK.

Many of the river banks and levees that were breached during Typhoon Hagibis have not yet been repaired.