Authorities urged residents of Chiba Prefecture to remain alert for landslides and flooding Friday even after emergency warnings were downgraded, as record-breaking rain left at least four people dead and disrupted transport and power supply across the region.

The Japan Meteorological Agency (JMA) lowered its Level 5 emergency heavy rain warning for 22 municipalities in Chiba, as well as emergency landslide warning for six cities, early Friday after the most intense rainfall eased. Of those municipalities, 11 have had the warning downgraded to Level 4 or Level 3, while the remaining 11 have had theirs removed entirely.

Still, unstable atmospheric conditions are forecast to persist across the Kanto region as well as the neighboring Nagano and Yamanashi prefectures through early Saturday, raising the risk of more heavy rain. As much as 150 millimeters of rain is forecast for southern Kanto in the 24 hours through 6 a.m. Saturday, with 120 mm possible in northern Kanto and 80 mm in Nagano and Yamanashi.

Four people were confirmed dead in the cities of Ichikawa, Sakura and Yachiyo, according to the Chiba Prefectural Government. One person remains missing and another was determined to have experienced cardiopulmonary arrest.

Rain battered Chiba from Thursday evening, with bands of intense rain clouds repeatedly forming over the prefecture. The city of Chiba’s Chuo Ward received 367 mm of rain in the 12 hours through 9:40 a.m. Friday, a record-breaking amount.

The deluge caused widespread disruption across the prefecture. Chiba’s governor requested a Self-Defense Forces disaster relief deployment at 5 a.m. Friday to help transport about 4,000 people stranded at JR Soga Station to a temporary shelter at the Chiba Prefectural Cultural Hall.

Approximately 7,000 passengers were stranded overnight at Narita Airport after train and bus services were suspended, NHK reported. JR East canceled or reduced services on several lines Friday morning, and delays were also reported on other lines. Road closures were reported after landslides as well, according to expressway operator Nexco.

About 24,000 households in Chiba, Ibaraki and Tochigi prefectures were without electricity at 10:30 a.m. Friday.

Officials are continuing to urge residents to watch out for landslides, overflowing rivers and flooding in low-lying areas.