The United Arab Emirates said on Monday that Qatari fighter jets intercepted an Emirati civilian aircraft during a routine flight to Bahrain, state news agency WAM reported, escalating a months-old feud between the Gulf Arab states.

The UAE Civil Aviation authority condemned the alleged incident and said it would take "all necessary legal measures to ensure the safety and security of civil air traffic."

A Qatari foreign ministry official denied the charge by the United Arab Emirates that Qatari fighter planes had intercepted an Emirati civilian plane en route to Bahrain, while on Al Jazeera TV.

The UAE is one of four Arab countries including Saudi Arabia, Bahrain and Egypt that imposed travel, diplomatic and trade sanctions on Qatar in June 2017, accusing Doha of supporting terrorism. Qatar has denied the charges.

On Friday, Qatar filed a complaint to the United Nations about an alleged violation of its airspace in December by an Emirati military aircraft.

Qatari authorities said the violation on Dec. 21, which the UAE denied, lasted one minute.