SANAA, Yemen -- Saudi-led coalition warplanes pounded Shiite rebels and their allies overnight and early Tuesday in the Yemeni capital, Sanaa, and in the south, while officials loyal to the country's exiled government criticized past attempts by the coalition to airdrop weapons to pro-government fighters in Yemen.

Since March 26, an alliance of the kingdom and several mostly Gulf Arab countries has been carrying out daily airstrikes against Yemen's Shiite rebels, known as Houthis, and their allies, army units loyal to ousted President Ali Abdullah Saleh. So far, the U.S.-backed campaign has failed to reign in the Iran-backed rebels who last year captured Sanaa and much of the country's north.

Overnight, multiple explosions shook Sanaa as warplanes dropped bombs, targeting several rebel-held army camps, trucks carrying weapons and houses turned into weapons' depots for the Houthis, according to residents and officials.

The residents, speaking on condition of anonymity because they feared for their own safety, said heavy smoke blanketed Sanaa. In the city's northern district of al-Nahda, several strikes hit large caches of weapons stored inside villas of two top Shiite rebel leaders, officials said.

The airstrikes also continued Tuesday in the southern port city of Aden, where poorly trained and lightly armed pro-government fighters have been resisting a siege by the Houthis, and also in the western city of Dhale.

Fighters battling the rebels on the ground around Aden and Dhale have said that they are running out of ammunition, according to local officials loyal to President Abed Rabbo Mansour Hadi, now in exile in Saudi Arabia.

Past attempts at airdropping weapons to pro-government fighters have failed and the arms have often ended up falling into the wrong hands, including those of al-Qaida's Yemen branch, the terror network's most dangerous offshoot, pro-Hadi officials said.

Mohammed Maram, head of the presidential office, held a meeting in Aden with governors of four southern provinces and top military commanders, including Maj. Gen. Ali Nasser Hadi, who described the past airlifts as a "failed and unorganized process."

Sanaa, Aden and Taiz --the third largest city in Yemen -- have been declared "disaster zones" by the internationally-recognized government in exile where humanitarian situation is on verge of collapse.

The attendees at the Aden meeting said at least two other cities should be added to the list -- Abyan and Lahj -- and described the situation there as bad.

Meanwhile, a Saudi soldier was killed and another wounded in a gunfight with the Houthis along the kingdom's southern border with Yemen, according to a Saudi security official. No further details were given about where or when the fighting took place.

At least seven other Saudi soldiers have been killed in separate clashes this month along the Saudi-Yemen border. Saudi troops, including a new deployment from the kingdom's National Guard, largely are positioned in the regions of Najran and Jizan.

All officials spoke on condition of anonymity because they were not authorized to speak to the media.