Aircraft from the Saudi Arabia-led coalition continued to hit Yemen on Thursday, two days after Riyadh announced the supposed end of a bombing campaign which has killed hundreds of civilians.

Coalition jets attacked tanks belonging to Yemeni rebels near the southern port city of Aden, as well as bases and weapons stores in the region surrounding the central city of Ibb early on Thursday, according to local residents who spoke with Reuters.

Airstrikes also took place on Wednesday, targeting the rebels near the capital of Sanaa, as well as around the cities of Taez and Yarim, witnesses told AFP. The attacks came as the World Health Organization said deaths from the fighting had topped 1,000 in the last month and the country's hospitals would soon be forced to close due to critical shortages of power and oxygen.

Saudi Brig. Gen. Ahmed al-Assiri said on Tuesday the country's "Decisive Storm" military offensive — which has been criticized for killing civilians and apparently violating rules of war — had reached a successful conclusion and would now make way for the Orwellian-sounding operation "Renewal of Hope". The next phase is described as being focused on protecting civilians and finding a diplomatic solution to the ongoing crisis, but officials later said they would continue to launch strikes in response to aggression from Yemeni rebels, known as Houthis.

The Houthis are allied with militias and army remnants loyal to ex-ruler Ali Abdullah Saleh — who was ousted in 2012 by an Arab Spring-inspired uprising — and are widely believed to be backed by Iran. They are currently battling troops and militias loyal to exiled President Abedrabbo Mansour Hadi, who took over from Saleh but resigned last January amid pressure from the Houthis. Hadi is currently in Riyadh but is internationally recognized as Yemen's legitimate leader.

The Saudi-led coalition includes troops from Qatar, Jordan, Bahrain, the United Arab Emirates, Egypt, Kuwait, Morocco and Sudan. Washington has said it is providing logistics and intelligence help, according to a Wall Street Journal report earlier this month.

Fighting between the rival Yemeni sides continued on Wednesday and Thursday, according to a number of reports, with clashes taking place in a number of regions, including around Aden, leaving a number dead.

Houthis and their supporters protested the airstrikes during a demonstrations in Sanaa on Wednesday. "We took to the street to condemn shelling [of] the civilians, bombarding [of] the residential areas," a Houthi and Saleh loyalist named Jamal al-Heefi, told Al Jazeera. "We are telling them, 'shame on you.' Why don't you face us on the ground? Why don't you fight like men? We will always face you as the Yemenis are solid like rocks."

Millions have been affected by the conflict according to the United Nations, with 60 percent of Yemen's population now in need of humanitarian assistance. Houthi leaders have said they are willing to enter UN-sponsored talks to end the conflict, but only if the air campaign stops completely.

Human Rights Watch (HRW) said on Thursday that a coalition strike that killed one man and destroyed an Oxfam warehouse in Saada containing humanitarian aid on April 18 appeared to have violated the laws of war.

The facility's location had previously been given to the coalition to avoid it being targeted and local residents told HRW that they had not been aware of any military targets in the area.

The group's deputy Middle East and North Africa director Joe Stork called for an impartial investigation from the nations involved in the bombing. "Destroying an aid group warehouse harms many civilians not even near the strike zone and threatens aid delivery everywhere in Yemen," Stork said. "Saudi statements that aerial attacks are over don't end obligations to investigate alleged laws-of-war violations."

If the warehouse was targeted deliberately, the strike would constitute a war crime.

Yemen's political transition since the ousting of autocrat Saleh's had been widely seen as a rare Arab Spring success story. But the impoverished state has been increasingly troubled since the Houthis swept down from their northern homelands in September and overran Sanaa. The avowedly anti-America and anti-Israeli rebels are accused of being used by Saleh to restore his power and influence in the country.

Iran's apparent support of the group have led officials in Tehran, including President Hassan Rouhani, to condemn the coalition air campaign. However it has shied away from providing the revels with military assistance.

US Defense Secretary Ash Carter said on Wednesday, however, that a group of nine Iranian cargo ships currently heading towards Yemeni waters may be carrying advanced weapons for the Houthis, a move that would violate a UN Security Council resolution. He added that an American aircraft carrier is now being moved into the region to join a group of warships already deployed there. Carter refused to be drawn on questions as to whether it might forcibly stop one or more of the Iranian ships saying only that the US had "options". "We're not at that point. We're at the point of trying to get the parties back to the table," he added, according to AP.

The US fleet will apparently not be used to rescue thousands of Yemeni-Americans still stuck in the country, however. Washington has insisted that using government resources to evacuate the dual nationals would put both them and the personnel involved in too much danger. A State Department recently told Bloomberg that while it was sharing information with its citizens there about opportunities to leave, an organised evacuation would be too risky.

Other countries have arranged evacuations for their own citizens, including India, which transported a number of Americans out of the country.