Greece has closed off its airspace to flights from Libya until September, local media reported citing a looming NATO operation. The alliance however refuted “baseless rumors” of any combat op in Libya, which remains in turmoil since the 2011 intervention.

A notice to airmen (NOTAM) was issued by the Greek authorities on Wednesday, which bans Libyan flights from entering Flight Information Region Athens starting Thursday, the Greek media reported. Similar restrictions were reportedly imposed by Malta and Italy, although they will last till August.

An exception to the rule is made for military aircraft with special authorization, and emergency cases such as evacuations for medical reasons, according to the Kathimerini daily. The newspaper claims the decision was made ahead of EU and NATO joint training in the Mediterranean. The Phoenix Express 2016 exercise is scheduled for the summer off the island of Crete.

The explanation, however, doesn’t convince some observers, who believe that the alliance is preparing a new full-fledged military intervention in Libya. The Greek communist party demanded that the government clearly state whether NATO is preparing such an operation and what would the country’s part in it would be.

The party “denounces any intervention in Libya and demands not to take part in the Euro Atlantic plans,” it said in a statement.

Following the reports of NATO’s possible involvement in the airspace closures, the alliance’s spokesperson Oana Lungescu took to Twitter to refute them as “baseless rumors” and “disinformation.” In a number of tweets to the media she insisted that “NATO has not requested any airspace closure and is not planning any combat operation in Libya.”