SANAA, Yemen (AP) — Airstrikes by the Saudi-led coalition fighting Yemen's Shiite rebels targeted the presidency building in the heart of the Yemeni capital on Monday, leaving at least six people dead and 30 wounded, according to health officials.

The officials, who spoke on condition of anonymity because they were not authorized to brief the media, said the six killed were all civilians. It was not known if there were any Houthi rebel leaders present at the time of the airstrikes in Sanaa or if any were killed or wounded. 

The three-floor presidency building was completely flattened, while surrounding buildings in the city's busy Tahrir district — including a famous five-star hotel — were heavily damaged. Cars were charred and pools of blood covered the pavement.

Many were believed to have been buried under the rubble, as ambulances rushed to the area to retrieve the casualties.

Saudi officials later said they had targeted high-ranking rebel officials who had been there and that several must have been killed.

"Intelligence was behind this targeting of the presidential palace in Sanaa, and Houthi leaders were there," Col. Turki al-Maliki told a press conference in Riyadh.

The Norwegian Refugee Council, an aid group operating in Yemen, said it was "appalled by Saudi-led coalition strikes on a highly-populated business district in Sana'a earlier today."

"We abhor the ongoing use of violence to intimidate civilian populations under the guise of efforts to protect them. Yemeni people are not collateral. Adherence to the laws of war is not optional," Suze van Meegen, the group's acting country director, said in a statement.

The Saudi-led coalition has been at war with the Houthis since 2015, hoping to restore the country's internationally recognized government. The war has killed over 10,000 people and driven 3 million from their homes.

Last month, the coalition killed a top Houthi leader, Salah al-Sammad, in the Red Sea port city of Hodeida. Al-Sammad was also the acting president of the territory under rebel control. The Houthis' leader, Abdel-Malek al-Houthi, has mostly kept out of the public eye, addressing Yemenis only in occasional newscasts on rebel-run outlets.

Monday's airstrikes appeared to have targeted al-Sammad's successor, Mahdi al-Mashat.

Witnesses described a scene of devastation. One resident said he saw a body thrown by the force of the blast against a shop and a car washer killed by shrapnel. The eyewitnesses spoke on condition of anonymity, fearing reprisals.

Windows of surrounding houses were shattered, while the nearby Sheba hotel had its entrance door blown out. Security forces cordoned off the area and kept journalists from approaching.

The sprawling presidency compound consists of several buildings walled off from the rest of the district.

Images that surfaced on social media in the aftermath of the strikes show bloodied faces of the wounded and columns of smoke rising over Sanaa.