The Daesh group claimed responsiblity for deadly attacks Tuesday on the government headquarters and positions of the Saudi-led coalition in the Yemeni city of Aden.
In a statement posted online, the Sunni extremist group said it carried out four suicide bombings against the targets, contradicting accounts from officials that the attacks involved rockets fired by Iran-backed Shiite rebels.
IS said two attacks targeting the government headquarters at Al-Qasr hotel were carried out using bomb-laden vehicles driven by members it identified as Abu Saad al-Adani and Abu Mohammed al-Sahli.
The jihadist group, which controls large parts of Iraq and Syria and has affiliates elsewhere in the region, said soldiers were killed in these attacks, without specifying how many.
Prime Minister Khaled Bahah, who escaped the attack on the Al-Qasr, wrote on his Facebook page that two rockets had hit the hotel while other rockets fell elsewhere.
IS said a third suicide bomber, Aws al-Adani, drove a bomb-laden armoured vehicle into a "central operations headquarters of Saudi and Emirati forces, killing dozens".
Meanwhile, Abu Hamza al-Sanaani blew up a UAE-held military position using another armoured vehicle, the group said.
The Emirati WAM news agency has reported that the attacks were carried out by the Iran-backed Huthi rebels and their allies.
The rebels "targeted the government headquarters and several military positions (and) left 15 Arab coalition and Yemeni resistance martyrs," said WAM.
The news agency said four Emirati soldiers were among the coalition forces that were killed and that several others were wounded.
The coalition said, in a statement published on the Saudi SPA news agency, that the attacks killed three Emiratis and one Saudi soldier.
It said Katyusha rockets had been used, and that coalition forces "responded to the source of fire and destroyed the vehicles" used to launch the assaults.
There was no immediate comment from the coalition on the IS claim.
Tuesday's claim is the first from IS for an attack against the Saudi-led coalition that has been bombing Iran-backed Shiite rebels since March.
Previously it only claimed attacks against Shiite mosques in Yemen.
The UAE and Saudi Arabia are among other Arab states taking part in a US-led coalition pounding IS in Syria and Iraq.
On September 4, a rebel missile attack in the eastern Yemeni province of Marib killed 67 coalition troops, including 52 Emirati soldiers.