DUBAI — Authorities in the United Arab Emirates have arrested Qatari “spies,” an Emirati daily reported on Wednesday in a new sign of mounting tensions between Doha and its Gulf neighbors.

The report in Al-Khaleej newspaper, which cited Emirati sources, was in response to a report in Qatar’s Al-Arab daily that three Qataris had been subjected to “arrest and torture” in UAE capital Abu Dhabi.

They were “Qatari intelligence elements operating on UAE soil,” Al-Khaleej wrote on its front page. “They were arrested and are being questioned.”

Qatar has confirmed the arrest in the UAE of two of its citizens, Hamad Ali al-Hamadi and Yousef Abdelsamad al-Mulla.

Qatar’s ambassador to the UAE has been tasked with investigating the fate of the pair, the spokesman said, without giving further information.

Relations between Qatar and its Gulf neighbors Saudi Arabia, the UAE and Bahrain sunk to a new low in March when the three governments recalled their ambassadors from Doha.

They accused Qatar of meddling in their internal affairs and supporting the Muslim Brotherhood, designated as a terror group by Egypt in December after the military’s ouster of Islamist president Mohamed Morsi, in a move mirrored by the Egyptian army’s Saudi backers.