Germany is ready to continue practice drills on protection of critical infrastructure in Estonia, the German military said on Monday, as a first such exercise dubbed “Baltic Tiger” was about to wrap up.

Since Oct. 3, German marines and airmen have been training how to secure airports such as the base in Aemari, the harbour in Tallinn and other locations together with soldiers from Estonia, Britain, Denmark and Belgium.

The German military said the drills were planned before last month’s suspected sabotage of the Nord Stream pipelines carrying Russian gas to Europe, which spurred European countries to ramp up protection of their critical infrastructure.

The chief of the German navy, Jan Christian Kaack, said he agreed with his Estonian counterpart that it would make sense to continue regular drills but that a final decision had yet to be taken.

He was echoed by German air force chief Ingo Gerhartz.

“Especially in these times, it is very important to demonstrate in Estonia, but also in the entire Baltics, that we stand at their side and are able, should a crisis arise, to reinforce our forces here in no time,” he told reporters.

Estonia has a coastline of 3,800 kilometres along the Baltic Sea and shares more than 300 kilometres of border with Russia.

“Here at Aemari Air base, we are just 10 flight minutes away from the Russian border,” Gerhartz said.

“What use would the best and most modern Eurofighter be if the airport we are operating from, here in Aemari, were not safe?,” he said. The base hosts five German Eurofighter jets as part of a NATO mission to protect the Baltic states’ airspace.

NATO warned Moscow on Oct. 11 it would meet attacks on allies’ critical infrastructure with a “united and determined response”.

NATO Secretary-General Jens Stoltenberg also pledged to boost the protection of critical infrastructure, saying the alliance had already doubled its presence in the Baltic and the North Seas to over 30 ships supported by aircraft and undersea activities.

Russia, which built the pipelines with foreign partners, also says the damage was caused by sabotage but has pointed at the United States and its allies.