Saudi-led air strikes against Houthi rebel targets have continued unabated in Yemen, hours after the Red Cross called for a 24-hour ceasefire to give aid workers a chance to address the growing crisis in the country.

The aerial bombardment, which reportedly focused on the capital Sanaa, came as the United Nations Security Council met on Saturday to discuss Russia's draft resolution that calls for "regular and obligatory" breaks in air strikes.

Hisham al-Omeisy, a youth activist based in Sanaa, told Al Jazeera that the air strikes on Saturday were the heaviest he had witnessed since they began 10 days ago.

"To make matters worse, the targets are not just the military bases in the capital, they are also political bureaus of the Houthis around the city" in residential areas, Omeisy said.

Fighting between rebels and forces loyal to President Abd-Rabbu Mansour Hadi for control of the southern city of Aden also continued on Saturday.

The International Committee of the Red Cross said on Saturday that there was an urgent need for fighting to halt in the worst-affected areas, including Sanaa and Aden.

'Humanitarian crisis'

Marie-Claire Feghali, a spokesperson for the Red Cross in Sanaa, told Al Jazeera that her organisation was finding it hard to bring in medical supplies.

"The humanitarian situation is extremely difficult and is getting more difficult by the day," she said. Feghali added that many wounded people were not getting medical supplies and that "hospitals are overwhelmed".

Yemen has been reeling from violence, with Houthis who forced Hadi to flee the country to Saudi Arabia, fighting to expand their control while forces backing the president are battling the rebels.

The Houthis, who belong to the Shia sect, swept into Sanaa last September and forced Hadi to flee his presidential palace for Aden, where he has a power base.

Timeline: The rise of Yemen's Houthi rebels

A Saudi-led coalition seeking to reinstate Hadi began bombing Houthi positions on March 26 and its planes have been dropping weapons to forces loyal to the president.

The UN says more than 500 people have been killed in the past two weeks and nearly 1,700 wounded. Residents in Aden say parts of the southern port city have been without water or electricity for two days.

Russian resolution

Russia on Saturday presented a draft resolution to the UN Security Council calling for a pause in the Saudi-led air campaign to allow the evacuation of foreigners and rapid, safe and unhindered access to allow humanitarian assistance to reach people in need.

Saudi Arabian Brigadier General Ahmed al-Asiri, a spokesman for the Arab coalition, told a news conference that aid "will come when we are able to set the conditions [so] that this aid will benefit the population".

He said the coalition requires that aid delivery does not interfere with the military operation, that aid workers are not put at risk, and that supplies do not fall into the wrong hands.

"We don't want to supply the militias," Asiri said.

The coalition bombing Houthi positions involves five members of the Gulf Cooperation Council - Bahrain, Kuwait, the United Arab Emirates, Qatar and Saudi Arabia. Oman, another member of the GCC, is not part of the coalition.

Other countries that have pledged support include Egypt, Jordan, and Sudan.