Watch: BBC reports from the front-line of an escalating war in Yemen

In rare access to Yemen's conflict zone, the BBC has travelled with government forces from Taiz through checkpoints to the line where the Houthi control ends and no man's land begins.

Saudi-backed pro-government forces are battling to push back Houthi fighters, who swept down the coast of the Red Sea earlier this month, taking control of a key shipping chokepoint and escalating Yemen's civil war.

From the front-line a drone is heard above, which a soldier accompanying the crew in south-western Yemen said is usually followed by an attack.

Within about 10 minutes, after the crew had driven away, the loud thuds of strikes followed, senior international investigations correspondent Nawal Al-Maghafi reports.