tropical storm

Tropical Storm Kai-tak, known locally as Urduja, battered the area on Saturday with heavy rains, strong winds and flash flooding.

One police officer told AFP news agency "rocks as big as cars" had been dislodged by the rainfall.

About 88,000 people were forced to leave their homes ahead of the storm.

The storm has also disrupted ferry services, disaster officials said, leaving more than 15,000 passengers stranded, many of them trying to reach home for the Christmas holidays.

However, the storm weakened on Sunday and was downgraded to a tropical depression.

Evacuation centres have been opened in both territories and residents have been urged to secure their properties and stock up on supplies.

Extensive flooding has been reported in Guam, after four inches of rain fell on the island today.

Goni is currently about 185 kilometres east, northeast of Guam and about 120 kilometres south, southeast of Saipan, which is still reeling from a direct hit by category three typhoon Soudelor two weeks ago.

The latest storm comes only two weeks after the Northern Marianas was struck by category three typhoon Soudelor, which caused extensive damage.

Michael Ziobro, from the US National Weather Service on Guam, says the storm is moving north, northwest at about 14 kilometres an hour and is projected to pass over Tinian and Rota early on Sunday.

Mr Ziobro says people in both the Northern Marianas and Guam should expect potentially damaging winds and heavy rain.