More than 34,000 people were staying in evacuation centers in an eastern Philippine province as the country's most active volcano spewed fiery lava for the fourth day, officials said yesterday.

The displaced residents were from seven towns and cities located near Mayon Volcano in Albay province, 330 kilometers south of Manila, which first showed signs of unrest on Saturday when it ejected thick ash and hot gasses.

"For the past 24 hours, we have monitored lava flow and rock fall events at Mayon," Renato Solidum, director of the Philippine Institute of Volcanology and Seismology, said in an interview with Manila radio station DZMM.

"We are closely monitoring gas emission because if there is build-up, then we could see a hazardous explosion," he added.

Medical teams were closely monitoring evacuation centers for health concerns amid cramped conditions, while security forces were also on alert to ensure peace and order, local officials said.

In Legazpi City, Mayor Noel Rosal said the eruption has drawn a lot of tourists who want to see bright lava flowing from Mayon's crater.

"We expect more tourists to come since it's still safe to watch the eruption from a distance," he said.On Tuesday, an 81-year-old man who was among more than 2,000 displaced residents in Tabaco City was found dead in the elementary school building that was used as an evacuation center, police said.

The man was believed to have died of ailments related to old age, a police spokesman said.