NATO has once again been forced to scramble fighter jets as Russia launched another massive attack on Ukraine. Two Spanish F-18 fighter jets were sent into the skies overnight after Romania’s Ministry of National Defence detected an aerial target close to the country’s border with Ukraine.

The alert came amid a wave of Russian drone strikes across Ukraine, hitting Kyiv, Dnipro, Odesa and other parts of the country. At least 10 people were killed and more than 80 injured in Monday’s strikes, which included attacks on the National Academy of Sciences in Kyiv and a business centre in Dnipro. Romanian radar systems detected the aerial target north of Isaccea, near the river border with Ukraine, overnight on September 28-29. The Spanish F-18s, on duty as part of NATO’s Enhanced Air Policing mission, took off to monitor the situation. Authorities issued a RO-Alert warning to residents in northern Tulcea County at 1.51am, before the air alert ended at 2.10am. Romania’s Ministry of National Defence said no incursion into the country’s airspace was reported.

Suspected drone fragments were also discovered on Romanian territory following the overnight alert.

Fragments of an unidentified object, believed to possibly be a drone, were found on farmland near Gropeni in Brila County on Tuesday morning.

The incident was reported to emergency services overnight after a member of the public reported seeing an object fall before a fire broke out.

No casualties or material damage were reported, while authorities secured the area and a specialist team from Romania’s Ministry of National Defence investigated the debris.

It has not yet been established whether the discovery is connected to the aerial target which prompted the Spanish F-18s to scramble.

Romania’s defence ministry stressed that its radar systems had not detected any unauthorised incursion into the country’s airspace overnight.

The latest incident comes just days after Spanish F-18s were scrambled over Romania following another alert involving Russian drones close to the Ukrainian border.

Seven Spanish F-18s and around 190 military personnel are currently stationed at Mihail Koglniceanu Air Base on Romania’s Black Sea coast as part of NATO’s mission to protect the alliance’s eastern flank.

Under NATO’s “alpha scramble” protocol, the fighter jets must be airborne within just 15 minutes of an aerial threat being detected.

Lieutenant Colonel Borja Calvo, commander of Spain’s Paznic detachment, said the unit had dealt with more real alpha scramble incidents in three weeks than previous Spanish deployments had experienced in four months.

Speaking to EFE just two days before the latest alert, he said: “It seems likely these incursions are deliberate.”

He added: “Russia is testing NATO’s response, whether these violations become normalised or not. And our response has been immediate every time.”

Read More: NATO scrambles fighter jets as Russia launches massive attack – WW3 fears explode