Yemen's Houthi fighters have threatened to undertake suicide bombings in Saudi Arabia if the kingdom continues to launch airstrikes against the group's positions.

Abdel Mon'em Al-Qurashi, a senior member of the Houthis Executive Committee, said on Saturday that the group would destroy the Saudi regime for its "aggressive" policies, Iran's Fars news agency reported.

"If Saudi Arabia continues its aggressions against the oppressed Yemeni people, [Houthi] fighters will pave the way for the Saudi regime's destruction by conducting martyrdom-seeking operations inside Saudi Arabia in the coming hours," Quraishi told Fars.

The threat came as the spokesman for the Arab coalition bombing Houthi targets in Yemen, Brigadier General Ahmed Asiri, said Houthi fighters were mobilising towards the Saudi border.

"Saudi forces are trying to deter the Houthis from mobilising in areas near Jizan and Najran using artillery and apache helicopters," Asiri said.

"We will not allow the Houthis to bring their forces near the southern border of Saudi Arabia."

Saudi-led airstrikes have bombed Houthi targets for three consecutive nights, in what they call Operation Decisive Storm, after assembling a coalition of more than 10 countries, five of them members of the six-nation Gulf Cooperation Council.

On Saturday, airstrikes hit Sanaa International Airport and the adjoining military airport, causing damage to planes, airport infrastructure and runways.

The airstrikes hit multiple provinces in Yemen, including Houthi strongholds and the bases of army units loyal to the group's main ally, former President Ali Abdullah Saleh.

In the southern coastal city of Aden, several people were killed on Saturday after a series of blasts rocked an arms depot at the foot of Jabal Hadid mountain overlooking Aden.

The cause was not immediately clear but residents had been looting the arsenal of Soviet-era weapons.

Troops guarding the depot had abandoned their posts earlier this week after their commanders fled.

According to the Houthi-run interior ministry, at least 24 civilians were killed in Friday's strikes, bringing the toll from Thursday and Friday to 45 civilians.

The figures of civilian and combatant casualties could not be independently confirmed, though Amnesty International said at least six children were among those killed in Sanaa on Thursday.