Governor Joey Salceda, whose province of Albay includes Mayon, said 2,400 tourists a day had been pouring into the area since the famously active volcano started oozing lava on December 14, compared with about 200 a day before.

"All the hotels are fully booked, even the cheapest ones," Salceda told AFP.

He said that tourists typically stayed only overnight to view the crimson lava oozing from the volcano's crater in the dark.

"It is like a slow moving meteor show. You really feel awe when you see it."

However Salceda said many tourists were also slipping by security patrols to enter the eight-kilometre (five-mile) danger zone around Mayon to get a close-up experience of the slow-moving lava column.

"There are enough thrill-seekers and, when you combine them with some enterprising local guides, they find their way in," he said.

The military heightened security around Mayon, about 330 kilometres (200 miles) southeast of Manila, on Monday after two foreign tourists were seen over the weekend riding all-terrain vehicles towards the volcano.

Salceda warned that although the lava was slow-moving, there was still a danger from volcanic ash that could mix with rainwater to form a lethal, fast-moving mudflow.

Such a mix has claimed hundreds of lives in the past, most recently in 2006 when a powerful typhoon dislodged tonnes of debris from Mayon slopes three months after an eruption, burying entire towns and killing over 1,000 people.

"It's a big problem. I think the first violation of the zero casualty (record) will be a dead tourist," said Salceda.

"At the moment of the eruption, the local guides will have better chance of getting out. The hapless tourist will be left behind."

But Salceda said the influx of tourists hardly made up for the economic dislocation caused by the volcano and the mass evacuations.

"It's a countervailing benefit to what is a negative economic event. At least there is that recovery," he said.

He complained that tourists stay for such brief periods and don't bother to spend more in the region.

Nearly 50,000 villagers living in Mayon's foothills have already been evacuated to areas outside the so-called "danger zone" this month, with troops posted at checkpoints to keep people from entering.

Civil defence officials have warned that these people may have to stay in evacuation centres for months as Mayon has traditionally simmered for prolonged periods rather than having one big eruption.

The US embassy said it was providing 100,000 dollars in aid to the families displaced by the volcano.

The funds will be used to provide food, shelter, water and sanitation assistance for up to 47,000 people, an embassy statement said.

Government volcanologist July Sabit, part of the team monitoring Mayon, said the volcano appeared to be experiencing a lull and was not as active as in previous days.

"(But) the volcano is still restive. The lava flow still continues," he warned.

"It is still at alert level four," he said, meaning a major eruption could occur at any time.

The 2,460-metre (8,070-foot) volcano, which is famed for its near-perfect cone, has erupted 48 times in recorded history. In 1814, more than 1,200 people were killed as lava buried the town of Cagsawa.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.