JAKARTA, June 1 (Xinhua)-- Rumbling Sangean volcano in central Indonesia has kept rising its seismic activity since Friday's eruption with volcanic ash spread toward east, drawing concern it may halt flights in the areas.
Powerful burst of hot ashes erupted by up to 3,000 meters high from the volcano located in a small island of West Nusatenggara province on Friday, according to Head of National Volcanology Agency Muhammad Hendrasto.
"By up to 10.42 a.m. local time, the seismic activity has kept rising. The ashes also spread toward Sumba Timur of East Nusa Tenggara province (east of the volcano)," Sutopo Purwo Nugroho, spokesman of national disaster agency told Xinhua via phone on Sunday.
Sutopo said the eruption forced more than 7,000 people to flee home and incurred the closure of two local airports.
"The number of evacuees so far stands at 7,328," he said.
Sutopo said displaced persons included 135 growers cultivating land in the small island with their plantations located in the slope of the volcano.
"Two airports in West Nusatenggara, the Bima airport and the Tambolaka airport both are closed," said the official.
Indonesian transport ministry has yet to issue a warning on flight.
The ministry regularly issues flight warning due to eruption of volcanoes in the vast archipelago country, including the recent one, when Sinabung volcano in North Sumatra erupted intermittently from September to February.
Sutopo said the ashes from Mount Sageang also enveloped Bima, a major city in the West Nusatenggra province, and other areas passed by the volcanic ashes.
To prevent the impact of the eruption on people's health, the local disaster agency has distributed over 15,000 masks, he said.
Mount Sangeang of 1,842 meters has been the third highest alert level since June 14, 2013, said Hendrasto.
"With this eruption we are likely to raise the alert level to the second highest," he said.
Mount Sangeang is among 129 active volcanoes in Indonesia, which is prone to seismic upheaval due to its location on the Pacific Ring of Fire, an arc of volcano and fault lines encircling the Pacific Basin.
In February, 15 people were killed and over tens of thousands others displaced when Mount Sinabung in North Sumatra erupted intermittently.