MANILA - Two areas in northern Luzon have been placed under storm signal no. 1 as Typhoon "Helen" further intensified, state weather bureau PAGASA said Sunday morning.

In its 11 a.m. advisory, PAGASA said the typhoon was packing maximum sustained winds of 140 kilometers per hour (kph) near the center and gusts of up to 175 kph.

Spotted 1,025 kilometers east of Calayan, Cagayan, "Helen" is expected to bring moderate to heavy rains within its 800-kilometer diameter, PAGASA said.

The weather bureau has hoisted public storm warning signal number 1 over Batanes and Babuyan Group of Islands, where winds of 30 to 60 kph may be experienced in 36 hours.

"Helen," however, is not expected to make landfall over extreme northern Luzon, according to PAGASA meteorologist Aldczar Aurelio.

Aurelio said the storm will instead head to Taiwan and will leave the leave the Philippine area of responsibility on Wednesday morning, if it continues to move west northwest at 22 kph.