A second Russian military jet has violated Turkish airspace in a mission that Nato says “does not look like an accident”.

The incident on Sunday follows a similar incursion on Saturday, where Turkey scrambled two Turkish F-16 jets to escort the Russian aeroplane out of Turkish airspace and into Syria.

Turkey has again summoned the Russian ambassador for a reprimand over the issue.

Russia said the incursion on Saturday was only for a few seconds and due to bad weather, but has not yet made a statement about the incident on Sunday.

Meanwhile, Nato has urged Russia to end its campaign of air strikes within Syria, where the Russians claim to target the Islamic State, but intelligence sources and civilians on the ground say instead target all anti-Assad rebel groups, including US-backed moderate groups currently fighting against IS.

In a statement, Nato said:

“Allies expressed their deep concern with regard to the Russian military build-up in Syria and especially the attacks by the Russian Air Force on Hama, Homs, and Idlib which led to civilian casualties and did not target Da’esh (IS). Allies call on the Russian Federation to immediately cease its attacks on the Syrian opposition and civilians, to focus its efforts on fighting ISIL, and to promote a solution to the conflict through a political transition.

“Russian military actions have reached a more dangerous level with the recent violations of Turkish airspace on 3 October and 4 October by Russian Air Force SU-30 and SU-24 aircraft in the Hatay region. The aircraft in question entered Turkish airspace despite Turkish authorities’ clear, timely and repeated warnings. In accordance with NATO practice, Turkish fighter aircraft responded to these incursions by closing to identify the intruder, after which the Russian planes departed Turkish airspace.

“Allies strongly protest these violations of Turkish sovereign airspace, and condemn these incursions into and violations of NATO airspace. Allies also note the extreme danger of such irresponsible behaviour. They call on the Russian Federation to cease and desist, and immediately explain these violations.

Allies call on the Russian side to take all necessary measures to ensure that such violations do not take place in the future.”