Tropical Storm ''Ineng'' maintains strength as it moves west-northwest, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) reported on Thursday.

In Pagasa's fifth severe weather bulletin issued at 5 pm , the center of Ineng was last seen at 670 kilometers east of Casiguran, Aurora.

The tropical storm has maximum winds of 75 kilometers per hour and gusts of up to 90 kilometers per hour.

According to the weather bureau, Ineng is moving west northwest at 10 kilometers per hour.

Tropical cyclone wind signal number 1 was raised in Batanes, Cagayan including Babuyan Group of Islands, Isabela, Apayao, Kalinga, Northern Abra and Ilocos Norte.

Pagasa also reported moderate to occasionally heavy rains will be felt over Catanduanes while light to moderate with intermittent heavy rains will be experienced over Metro Manila, Ilocos Region, Cordillera Administration Region, Zambales, Bataan, Cavite, Batangas, Mindoro Provinces, northern portions of Palawan (including Calamian and Cuyo Islands), Antique, Aklan and the rest of Bicol Region.

On Friday, moderate to heavy rains are expected over Batanes, Cagayan including Babuyan Group of Islands, Ilocos Norte and Apayao.

Light to moderate with intermittent heavy rains may prevail over Metro Manila, Central Luzon, Cavite, Batangas, Mindoro Provinces, northern portions of Palawan (including Calamian and Cuyo Islands), and the rest of Ilocos Region, Cordillera Administrative Region and Cagayan Valley.

Residents in the affected areas are advised to take precautions and were urged to coordinate with local disaster risk reduction and management offices in case of landslides and flooding.

The weather bureau announced sea travel is still risky over the seaboards of Luzon.

Ineng is expected to leave the Philippine Area of Responsibility by Sunday afternoon. Cristina Eloisa Baclig/DMS