By Barry Malone
KAMPALA (Reuters) - A long-dormant volcano has erupted in Eritrea after a series of earthquakes and sent a 13.5 km plume of ash into the air, according to the Volcanic Ash Advisory Center (VAAC).
The volcano started to erupt around midnight on Sunday, charts on the website of France-based VAAC indicated.
The remote, arid region, close to the border with Ethiopia, was hit by a series of earthquakes earlier the same day, data from the United States Geographical Survey showed, with the biggest reaching 5.7 on the richer scale.
The Dubbi Volcano -- which is located 350 km north of the Eritrean capital Asmara and 233 km east of the Ethiopian city of Mekelle -- is thought to have last erupted in 1861.
The independent earthquake monitoring website, earthquake.com said it might be another nearby volcano nearby known as Nabro that was erupting and carried testimonies from residents in the region confirming the ash cloud.
"The plume from the volcano is covering the whole of Asmara since the morning, but now it is clearing somewhat," one resident was quoted as saying.
Dubbi's ash cloud hit an altitude of 13.5 km, VAAC said.
Ethiopian state media warned people to protect themselves from ash.
Ethiopia relocated more than 50,000 people in 2005 after a series of earthquakes and a volcanic eruption on its side of the border. As residents fled, hundreds of their animals were swallowed into crevices in the ground.
The Dubbi Volcano is located in a tectonic triple junction known as the Danakil depression that spans parts of Eritrea and Ethiopia.
Scientists say its spreading ridges, that form the Red Sea and the Gulf of Aden, may 10 million years form a new ocean and split Africa in two.
(Editing by Richard Lough)