ADDIS ABABA, Ethiopia—An Ethiopian Airlines spokesman said an East African volcanic ash cloud disrupted several flights on Tuesday, and an Ethiopian scientific official said the cloud has reached as far as southern Egypt and Sudan.

Ethiopian Airlines spokesman Getachew Tesfa said flights to Sudan’s capital, to Djibouti and to northern Ethiopia were on hold on Tuesday. He said other flights will continue.

The Volcanic Ash Advisory Center, which advises the aviation industry about volcano eruptions, said the volcano in Eritrea began erupting early Monday. Eritrea borders Sudan, Ethiopia and Djibouti. It has a population of about 5 million people.

Atalay Ayele of the Geophysical Observatory Center of Ethiopia’s Addis Ababa University said the size of the ash cloud is decreasing and that its direction is changing from northwest to southwest. He said it has now reached Egypt and Sudan.

Raul Romero, secretary of the Montreal-based International Airways Volcano Watch Operations Group, said the volcano that erupted on Monday has now been confirmed to be Nabro Volcano, not the Dubbi Volcano as was reported Monday.

He said the volcano was still erupting.

“Probably they declared it as Dubbi, but now the latest report, all of them, refer to Nabro,” he said.

The International Airways Volcano Watch Operations Group and the Volcanic Ash Advisory Centers both fall under the International Civil Aviation Organization.

The eruption prompted US Secretary of State Hillary Rodham Clinton to announce on Monday during a visit to Ethiopia that she was cutting short a three-nation African tour.