The Arab military coalition sent hundreds of ground troops as well as more tanks and other equipment into Yemen's oil-rich Marib province on Tuesday, military sources said.
The coalition led by Saudi Arabia and including Egypt, Jordan and Sudan has been bombing the Houthi militants who ousted the Yemeni government since March.
In recent days, it sent thousands of troops, Apache helicopters and hundreds of tanks and armored cars in support of the government forces seeking to drive the militants out of Marib and the adjacent province of Jawf.
Moreover, the Arab military support comes within the preparations for the battle to retake the capital city of Sanaa from the militants.
The sources said fighter jets from the coalition struck Houthi militants today killing many of them and destroying their equipment as the battles continued in Marib.
In Sanaa, the Houthi militants failed to launch a missile into Marib from the Al-Dailamy air base with eyewitnesses reporting that a missile landed within the base shortly after it had been fired.
We heard huge explosions and that there were casualties inside the base after the accident, an eyewitness said.
On the border cities, Gulf media said forces from the coalition have penetrated into Saada province, the Houthis' stronghold, seizing some areas in it.
Lately, spokesperson for the coalition, Ahmed Asiri, confirmed that forces from the coalition have repeatedly crossed the border into Yemeni lands.
Sporadic clashes and rocket-firing exchange between the Saudi army and the Houthis have been reported on the border for months.