ADEN: Hundreds of Yemeni troops trained in Saudi Arabia have crossed over the border from the kingdom and seized a rebel town after clashes that tested a shaky ceasefire, military officials said Friday.

The pro-government forces captured Harad, about 15 kilometers (nine miles) from the frontier, on Thursday with support from warplanes of the Saudi-led coalition, an official said.

About 1,000 soldiers are involved in the operation, the official said, adding that "intensive fighting took place in Harad".

He said dozens of renegade troops allied with the Iran-backed Huthi Shiite rebels had been killed.

The advancing force is now just a few kilometers away from the Red Sea port of Midi, which has been under rebel control since 2010, military sources said.

Clashes have been frequent along the border with Saudi Arabia, where rebel strikes have killed more than 80 people since March when the coalition campaign against the rebels began.

A fragile ceasefire has been repeatedly violated since it took effect on Tuesday to coincide with UN-sponsored peace talks being held behind closed doors in Switzerland.