The head of an international aid group says the number of causalities in Yemen from the Shiite rebel shelling of a town near the southern port city of Aden has risen to almost 100 people killed.

Hassan Boucenine of the Geneva-based Medicins Sans Frontieres, or Doctors Without Borders, gave the new toll on Monday. He says the number of wounded is now at 200.

Boucenine told The Associated Press that the victims are mostly civilians and that MSF fears "attacks on civilians will continue."

Shiites rebels, known as Houthis, and their allies started shelled the town of Dar Saad on Sunday after losing control of some of Aden's neighborhoods.