MANILA (Reuters) - The Philippines is preparing to evacuate residents along its northeastern coast as a typhoon approaches, as well as those near a rumbling volcano that has been spewing steam and ash over a central province, officials said on Friday.

Typhoon Noul was about 480km north-east of the town of Borongan in Eastern Samar province early on Friday, with wind gusts of up to 185 kmh, and was expected to make landfall as a category 4 storm at the weekend.

Thousands of passengers have already been stranded in seaports along the central and eastern Philippines after the authorities stopped vessels from sailing because of rough seas.

The typhoon, the fourth to hit the South-east Asian country this year, was expected to bring heavy to intense rainfall when it makes landfall in the north-east, the weather bureau said. It was then expected to weaken as it headed towards the Japanese island of Okinawa by Tuesday.

Officials warned that heavy rain from the typhoon could cause lahar, or flows of mud and debris, around Mount Bulusan, a volcano that has been spewing ash this week.

"There could be lahar flow, mudslides, that could sweep away houses in the area if there is heavy rain ... that is the danger," Mr Esperanza Cayanan, division head at the weather bureau, told a briefing at the national disaster agency.

Ms Fritzie Michelena, a disaster official in Irosin in central Sorsogon province where the volcano is located, said the municipality was getting ready to evacuate residents. "We will do pre-emptive evacuations because it might be difficult to get people out if we do it later," she said in an interview with the ANC news network.

Officials have designated schools and gymnasiums as possible shelters. Typhoon Noul was also expected to trigger landslides and flash floods, with government officials alerting regional offices along the storm's projected path by text, email and phone calls.

An average of 20 typhoons cross the Philippines annually. Super typhoon Haiyan was the most destructive in recent years, leaving more than 8,000 people dead or injured in 2013.

"We are praying to God that the typhoon will dissipate. We don't want to keep going back to evacuation centres," Ms Rosario Cajipe, who survived typhoon Haiyan, told ANC network in Tacloban City, south of the volcano.