Oct. 29 (Bloomberg) -- Philippines authorities warned of flooding and landslides as Typhoon Mirinae strengthened over the Pacific and bore down on the main island of Luzon, where more than 900 people were killed in two cyclones in the past month.

Mirinae’s winds increased to 160 kilometers (99 miles) per hour from 136 kph yesterday as it headed west toward Luzon, the U.S. National Weather Service said on its Web site. The storm was centered 917 kilometers east of Baler town on Luzon at 5 p.m. local time.

More than 121,000 people remain in evacuation centers after two cyclones barreled into Luzon, the most populous island, since Sept. 26, according to the country’s National Disaster Coordinating Council. Mirinae is forecast to hit the coast after midnight on Oct. 31 near Casiguran. Typhoon Lupit also approached Luzon last week before turning away.

The Philippine Coast Guard stepped up preparations because the typhoon’s landfall may coincide with All Saints’ weekend, when many Filipinos travel by boat and other means to their home provinces, Admiral Wilfredo Tamayo, Coast Guard commandant, said in a telephone interview.

The Coast Guard sent rescue divers to the eastern coast of Luzon where the typhoon is forecast to make landfall and to areas on the western coast of the island where Mirinae is forecast to exit, Tamayo said.

As many as 800 people were killed after a ferry sunk in June last year when Typhoon Fengshen slammed into the archipelago of more than 7,000 islands.

Storm Warning

Typhoon Mirinae presents a “special challenge” because it may be crossing Luzon during All Saints’ Day on Nov. 1, when Filipinos visit cemeteries to remember their ancestors, Defense Secretary Gilbert Teodoro told reporters yesterday.

Teodoro urged Luzon residents to avoid going out should warnings be issued. Police were ordered to set aside road lanes for disaster response teams, he said.

The government was criticized for a slow response after Tropical Storm Ketsana blew across Luzon late last month. Ketsana was followed by Typhoon Parma, which crossed Luzon three times earlier this month.

The Philippines weather agency raised its Storm Warning Signal No. 2, meaning winds of between 60 and 100 kph are expected for areas of eastern Luzon. Residents of low-lying and mountainous areas should take precautions to avoid flash floods and landslides, the agency said.

Mirinae’s winds are forecast to increase to 176 kph by 8 p.m. today, the U.S. weather service said.

Ketsana and Parma caused about 38 billion pesos ($803 million) in damage, the disaster council said yesterday.

To contact the reporter on this story: Aaron Sheldrick in Tokyo at asheldrick@bloomberg.net.

Last Updated: October 29, 2009 06:57 EDT