“So far we have recovered the bodies of three students, the bodies of the remaining [three students] are still being removed,” the source told the agency.

The targeted school was reportedly in a central province, located between Yemen’s capital, Sanaa, and the port city of Aden.

PressTV also reported the airstrikes hitting a school in Yemen’s central Ibb governorate, stating that at least six children were killed.

Similar reports were covered by the CNN, which cited Yemen’s officials as saying that the airstrike hit the school while targeting a nearby military base. At the time of the attack, children were on their way to lunch. The school is allegedly located just 500 meters from the base.

In late March, five Gulf states and Egypt launched airstrikes targeting Shiite Houthi rebels, who had seized the Yemeni capital and large territories in the west of the country. Jordan, Sudan, Morocco and Pakistan also expressed willingness to join in the military operation.

The death toll in Yemen has been climbing since the Saudi-led assault began, rising to at least 560 people dead and 1,768 wounded – most of them civilians – the World Health Organization (WHO) said Tuesday. Around 100,000 people are also said to have fled their homes.

The United Nations Children’s Fund (UNICEF) estimated that 74 children have been killed since the start of the airstrikes and 44 others have been injured.

‘Children being killed’

The humanitarian situation is worsening every day, spokeswoman for the Red Cross Marie Claire Feghali told AFP on Tuesday, describing it as “very difficult” with “naval, air and ground routes cut off.”

The atmosphere in Aden is “catastrophic to say the least,” she added. “The war in Aden is on every street, in every corner … Many are unable to escape.”

UNICEF’s Yemen representative, Julien Harneis, said that children are particularly vulnerable in Yemen.

“They are being killed, maimed and forced to flee their homes, their health threatened and their education interrupted,” according to a statement released on Monday.

Médecins sans Frontières (MSF) said that many injured do not have the infrastructure to reach local hospitals. MSF’s Marie-Elisabeth Ingres specified that hospitals in in Aden had “not received large numbers of casualties over the past few days … due to the difficulties faced in trying to reach a hospital.”

According to the Red Cross, it has been tough getting aid inside Yemen. Geneva-based spokeswoman for the Red Cross told AP on Tuesday that 17 tons of medical supplies are stored in a cargo plane in Jordan. It needs approval form the coalition in order to land in Sanaa. Another 35 tons is also ready to be shipped.

“If these medical supplies do not reach Yemen, then unfortunately we are afraid many more people will die,” Jabeen said.

US to step up arms deliveries to Saudi Arabia

The US announced on Tuesday that it is speeding up weapons supplies. It is also stepping up intelligence sharing with the Saudi-led coalition, US Deputy Secretary of State Antony Blinken said.

“Saudi Arabia is sending a strong message to the Houthis and their allies that they cannot overrun Yemen by force,” Blinken told reporters in the Saudi capital, Riyadh.

“As part of that effort, we have expedited weapons deliveries, we have increased our intelligence sharing, and we have established a joint coordination planning cell in the Saudi operation center," he said.

Colonel Steve Warren at the Pentagon added that existing arms delivery orders will be expedited.

“It’s a combination of pre-existing orders made by our partner nations and some new requirements as they expend munitions,” Warren said.

Overall, Saudi Arabia has been one of the top buyers of US weapons under President Barack Obama, totaling $46 billion in new agreements, according to a recent report by William Hartung, director of the Arms and Security Project at the Center for International Policy.

White House spokesman Josh Earnest said on Monday that “the US military continues to support the efforts of Saudi Arabia and some of their partners in the region to try to address the security situation along their border that they’re justifiably concerned about.”