MANILA, Oct. 15 (Xinhua) — The Philippine disaster agency on Saturday placed capital Manila under Alpha Alert as Typhoon Sarika intensifies and moves closer to Luzon island.

Alpha Alert is a classification on the level of preparedness of local government units in accordance with the so-called "operation list" of the Department of Interior and Local Government.

Also on Saturday, the state weather bureau raised the alert level to 3 in five areas on the direct path of the typhoon.

As of noontime Saturday, the bureau said the typhoon was spotted 20 km east northeast of Daet in Camarines Norte province.

It has a maximum winds of up to 130 km per hour and gustiness of up to 180 km per hour.

"Estimated rainfall amount is from moderate to heavy within the 500 km diameter of the typhoon," the bureau said, adding that "possible occurrence of storm surges along the coastal communities. "

The bureau also warned fishermen to avoid venturing into the rough seas.

The National Disaster Risk Reduction and Management Council said in a statement that the typhoon is "likely to intensify further into severe tropical storm (Saturday) evening."

"It is expected to make a landfall over Quezon-Aurora area by Sunday morning," the bureau said, warning of possible landslides and flash floods in affected areas.

So far, the disaster agency has recorded at least 4,000 stranded passengers in different ports of Luzon and Visayas region in the central Philippines.

The typhoon is expected to leave the Philippine area of responsibility on Monday, the bureau said.