MANILA, May 9 (Xinhua) -- Tropical storm "Rammasun", locally called "Butchoy", continued to gain strength Friday as it was moving northward in the high seas east to the Philippines, the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) said.

    As of 2:00 a.m. local time (1800 GMT), PAGASA tracked the storm east of Samar island in central Philippines and was moving north to Luzon at 11 kilometers per hour (kph).

    Late Thursday night, the center of the storm was placed at 500 kilometers east of Hinatuan, Surigao del Sur in southern Philippines, packing maximum sustained winds of 85 kph near the center and gustiness of up to 100 kph.

    The weather bureau forecast the storm to be 620 kilometers northeast of Hinatuan Friday night and 700 km east of Borongan, Eastern Samar Saturday evening.

    PAGASA said that despite the weather disturbance's intensified activity, no storm warning signal has been raised.

    The storm is also expected to induce the southwest monsoon that could bring rains over the Visayas in central Philippines and Mindanao in southern Philippines.

    PAGASA warned residents in low lying areas and those living near mountain slopes to take precautions against possible flashfloods and landslides.

    The Philippines is bracing for at least 20 typhoons or tropical storms this year, as is forecast by the PAGASA.

    The country was relatively spared from major tropical storms in2007, while several typhoons in 2006 killed hundreds of people.