Ash spewing from the Dubbi volcano in Eritrea has covered villages in Ethiopia, affecting at least 5,000 people, aid workers say.
Initial reports said eight villages in the Biddu district of Ethiopia, close to the border, were covered by volcanic dust.
Villagers have been left without food and traditional springs and streams have been polluted.
The Afar regional government says the numbers affected could rise sharply.
Save the Children told the BBC the authorities had sent a team to conduct a detailed assessment of the situation.
An initial report by the regional government says the situation in border villages is a serious concern.
“Many community members and especially children are reported sick and in desperate need of medical attention,” said Teshome Assefa, of Save the Children.
“Vomiting and retching are common.”
The whereabouts of one community living close to the eruption is unknown.
The Dubbi volcano has sent the plumes of ash 13km (eight miles) into the air.
In Related News:
Eritrea volcano eruption sends ash plume to Israel
The Dubbi volcano in Eritrea erupted last week and sent a plume of ash up to 15 kilometres into the air on Monday. People In the north of Israel were surprised on Tuesday morning to awake to rain, an extremely rare occurrence during the summer
The Dubbi volcano in Eritrea erupted last week and sent a plume of ash up to 15 kilometres into the air on Monday. The volcano began belching plumes of ash at about midnight on Sunday after a string of earthquakes.
According to scientists at the Israel Meteorological Service the volcanic ash cloud was heading toward Israel. According to current estimations, the ash cloud is moving high in the atmosphere, and will probably remain too high to cause any travel disruptions or changes in the quality of air.
Meteorologists confirmed that the ash cloud from an Eritrean volcano had indeed reached the Red Sea city of Eilat, but authorities insisted there was no health danger to civilians and also that flights at both Eilat Airport and Ben-Gurion International Airport were running on schedule.
In the north of the country, residents of the Golan and Galilee regions were surprised on Tuesday morning to awake to rain, an extremely rare occurrence during the summer months. The precipitation was accompanied by increased winds.
Source: BBC and port2port