By Sarah Toms
BBC News, Manila
Scientists in the Philippines have warned that Wednesday's full moon could spark a major eruption of the Mount Mayon volcano.
Mayon is the most active volcano in the Philippines
Experts say Mount Mayon, the most active volcano in the Philippines, could erupt at any time.
But the full moon's gravitational pull could trigger the eruption, they say.
A full moon coincided with at least three of Mayon's 47 eruptions, including the two most recent ones in 2000 and 2001.
The volcano has been spewing lava and flaming rocks the size of cars in a quiet but steady eruption since last month.
Some scientists say gravitational pull of sun and moon can influence eruptions
Influence is greatest at full and new moon
Others say more research is needed
The nearest village is now less than 2km from a trail of molten lava streaming down the crater.
Nearly 40,000 people have been moved from an 8km danger zone around the volcano.
Soldiers are appealing to reluctant villagers to leave their homes and farms around a rumbling volcano.
But still some people have refused to leave their livestock and farms.
President Gloria Arroyo has urged residents not to flirt with danger, saying evacuation centres were prepared to offer basic needs and services.
She says she is confident though there will be no casualties if Mayon erupts.
The volcano has erupted around 50 times over the past 400 years. One of the worst was in 1993 when at least 75 people were killed.