The Iranian-backed Houthi militias torched the Sadel Jabalain petrol plant which contain the main petrol and gas reserves in the southern province of Taiz, while pro-government forces advance towards the presidential palace in Aden, according to Al Jazeera.
Strong explosions were heard in the west and south of Taiz, as fire and smoke covered the region entering the central prison, residents said.
Sources said 3 million liters of petrol preserves were burnt by shellings of the Houthi rebels and fighters allying the former ousted Yemeni President Ali Abdullah Saleh.
The incident arose just a few hours after the self-exiled Yemeni President Abd Rabbuh Mansour Hadi took control of key districts in Taiz from Houthi fighters.
At least 22 civilians were killed and 30 were injured. Five Houthi fighters were captured and eight pro-Hadi fighters were killed, while 11 were wounded in the fierce clashes in Taiz, according to Al Jazeera.
Pro-Hadi fighters advanced towards the Presidential Palace which was under the control of the Houthis where intensive confrontations took place, the pro-Hadi Media Center in Aden reported.
Meanwhile, local residents said Saudi-led coalition air strikes attacked assemblies of Houthis in the Al Tawahi region on Saturday night
At least four pro-Hadi fighters were killed in the confrontation with Houthis fighters in the Maashiq Mountains in Kriter, where at least 20 Houthis surrendered, local official in Aden said.
On Saturday, a coalition aircraft bombed a convoy in attempt to reinforce the Houthis, east of Aden, killing 25 fighters, a military official said.
The Houthis took control of the Yemeni capital of Sanaa last September, before expanding to take control over more territory in the country.
Later, the Saudi-led coalition began an extensive air campaign targeting Houthi-held cities across Yemen on March 26 in order to allow president Abd Rabbuh Mansur Hadi and his government, who are in self-imposed exile in Riyadh, to return to Yemen’s capital Sanaa.
Pro-Hadi forces backed by Saudi-led air strikes took control of the Labuza army base in the Lahj province on Saturday, after a week of planning. The fighters were well-armed and trained by Saudi Arabia and the United Arab Emirates.
Houthi forces and their allies in Yemen's army attempted to regroup and take back the northern fringes of Aden on Friday, firing on the Khor Maksar district, but their offensive was repelled.
In the city of Aden alone, more than 858 Yemeni civilians were killed, including 259 children and 6,879 others were wounded in the first 100 days of the conflict.
Since the Saudi-led campaign of air strikes in Yemen started four months ago, at least 3,500 people have killed so far.