The advance on al-Dahida heights, a strategic highland, comes as fighting escalates in al-Dhalea, Lahij and Taiz.

Yemeni government forces say they have pushed further into the al-Dahida mountain range in eastern al-Jawf province, a day after claiming control of the heights in their offensive against the Houthis.

In a statement on Wednesday, the armed forces said troops backed by fighter jets and drones had stormed Houthi fortifications and barracks in the area and seized weapons and military equipment.

Air and drone strikes also targeted Houthi gatherings and depots at several sites, the statement said, claiming the Iran-backed group had suffered heavy losses.

The reported gains are the latest claimed in Operation Dawn of Yemen, which is now in its second month. Government forces spent weeks attacking Houthi positions and fortifications before announcing they had recaptured several strategic overlooks east of al-Hazm, the provincial capital.

Rashad al-Alimi, head of the internationally-recognised government’s Presidential Leadership Council, said the operation would continue until it had restored state institutions and the internationally recognised government’s authority over the whole country.

Fighting is escalating on several fronts.

A Houthi ballistic missile struck a military training camp in the southern province of al-Dhalea, killing eight people and wounding more than 15, a military source told Al Jazeera.

Al Jazeera’s correspondent, citing field sources, said the missile hit a gathering of recruits at the al-Jumaima camp in northern al-Dhalea. No official toll has been released, and some Yemeni media reported higher figures.

Government forces said they had carried out air strikes on Houthi positions in western Taiz province. In northern Lahij, they said they had recaptured positions in al-Maqatira district, which lies on a key defensive line linking Taiz with Aden, the internationally recognised government’s capital.

Houthi-affiliated media reported four air strikes on a Central Security Forces camp in the city of al-Bayda, and a strike on a health centre in al-Silw district in Taiz. The Houthis claimed strikes from Saudi Arabia, which backs the Aden government, had killed civilians over two days this week.

Yemen’s Interior Minister Ibrahim Ali Haidan said 21 foreign experts were directing Houthi operations: 14 from Iran’s Islamic Revolutionary Guard Corps (IRGC) and seven from Lebanon’s Hezbollah. Hezbollah rejected the accusation as “baseless”.

Meanwhile in Saudi Arabia, civil defence authorities twice activated early-warning sirens in the southern Najran region on Wednesday morning, after a similar alert overnight in the Riyadh region.

On Tuesday, the Saudi-led coalition said it had intercepted and destroyed a drone over Mecca. Houthi military spokesman Yahya Saree denied launching any attack on Saudi territory.

The United States embassy in Riyadh warned that Houthi attacks on the kingdom could escalate quickly. US government staff require special permission to use any airport in Saudi Arabia.