Pro-government forces have made a series of gains in recent weeks in southern Yemen with the help of a Saudi-led and US-backed coalition that has been waging an air campaign against the Iran-allied rebels and allied military units since March.
The officials say the rebels, known as Houthis, appear to have lost most of their heavy weapons in a battle Monday to defend the key military base of al-Anad in Lahj.
Houthi officials could not immediately be reached for comment.
Meanwhile in Taiz, Yemen's third largest city, five civilians were killed in clashes between rebels and pro-government troops at a state security building that the Houthis have been using as a base since March, medical officials said.
Pro-government forces have cordoned off the southern port city of Aden and set up security checkpoints. Those residing outside Aden are not allowed to enter the city for fear they may be "Houthi sleeper cells," a security official said.
