Shohdi Alsofi, Associated Press
In this photo take on Friday, April 17, 2015, smoke rises after a Saudi-led airstrike on Sanaa, Yemen. Iran's foreign minister urged U.N. Secretary-General Ban Ki-moon on Friday to try to end "the senseless aerial attacks" in Yemen by a Saudi-led coalition and establish a cease-fire.

SANAA, Yemen — Fighting and Saudi-led airstrikes targeting Shiite rebels struck Sunday across Yemen, officials said, as the United Nations said that Saudi Arabia had agreed to completely fund a $273.7 million appeal for emergency humanitarian aid to the county.

The combat, which intensified in late March when the Saudi-led coalition of majority Sunni countries began launching airstrikes against the rebels, known as Houthis, pits the rebels against forces loyal to exiled President Abed Rabbo Mansour Hadi.

In the southern port city of Aden, Yemen's second largest, pro-Hadi forces regained control Sunday of part of the coastline that had been held by forces loyal to rebel leader Abdul-Malek al-Houthi and former president Ali Abdullah Saleh, the security officials said. The gained positions allow them to attack the rebel-held airport and cut off supplies to anti-Hadi forces, they said.

Rebel forces also made another push to take the Dar Saad area, just north of Aden, but failed, the officials added, speaking on condition of anonymity because they were not authorized to brief journalists.

Later in the day, pro-rebel television station al-Masirah said that leader al-Houthi would speak Sunday night, which would be his first comments since the airstrikes began.

Meanwhile in Amman, the United Nations said Saudi Arabia had agreed to fund completely a $273.7 million appeal for emergency aid to avoid a humanitarian catastrophe inside Yemen.

The U.N issued the urgent appeal last week, saying it was needed to save lives and protect some 7.5 million people affected by the conflict and in dire need of medical supplies, safe drinking water, food assistance, emergency shelter and logistical support.

Purnima Kahsyap, humanitarian coordinator for the U.N. aid effort in Yemen, said that the U.N. was thankful to Saudi Arabia for covering the entire appeal cost, but urged all other partners to continue to provide assistance.

A Saudi-led coalition launched an air offensive against Yemen's Shiite rebels on March 26.

Associated Press writer Sam McNeil in Amman, Jordan, contributed to this report.