Qatar fighter jets harassed UAE military aircraft on three occasions in recent weeks, Emirati aviation officials said on Tuesday, branding the acts a violation of international law.
The previously undisclosed incidents preceded Qatar's interception of two Emirati civilian airliners on January 15, which led the UAE to file a complaint at the UN.
In a rare briefing about its operations, Brig Gen Helal Al Qubaisi of the UAE Armed Forces said a Qatari jet approached a UAE F-16 on December 27 last year.
"They claim the aircraft violated Qatari airspace. It didn't," Gen Al Qubaisi told reporters in Abu Dhabi, adding that the UAE plane was on a training mission. "They jeopardised lives."
The other two military incidents, on January 3 and January 12, involved a UAE Twin Otter aircraft and a C-130 cargo plane.
The general condemned what he called "aggressive action" by Qatar.
But in an attempt to avoid any escalation in the skies he said the UAE military was using other routes over Saudi Arabia to maintain its operations. Civilian airliners have not changed their routes.
The military incidents add to ongoing tension over last week's interception of the Emirates and Etihad airliners.
Ahmed Al Jallal, a high-ranking UAE civil aviation official who at the briefing produced a still photograph of an armed Qatar fighter jet, taken from the cockpit of one of the UAE planes, said such actions amount to "an unprecedented escalation".
The two UAE officials also rejected Qatar's explanation of the January 15 incident as being a legitimate training mission.
"We see this as an alibi," said Brig Gen Al Qubaisi, noting that US aviation monitors had passed that answer on to UAE. "We cannot accept that. It is a violation of international agreements."
Saudi Arabia, UAE, Bahrain and Egypt have cut all ties with Qatar over what they say is its support of extremism and interference in the affairs of other countries.
Qatar has so far refused to meet the quartet's 13 demands — including the closure of the Qatar-owned Al Jazeera news channel and the shutting down of a permanent Turkish military base in the country.