Germany and Finland have said they are “deeply concerned” about a severed undersea communications cable between the two countries, saying that it raised suspicions of possible Russian sabotage.

Cinia, the Finnish state operator of the 1,200km C-Lion1 fibre optic cable between Helsinki in Finland and Rostock in Germany, said it had been cut early on Monday morning in the Baltic Sea close to Sweden and was almost certainly the result of an “external force”.

In a joint statement, the foreign ministers of the two countries said: “We are deeply concerned about the severed undersea cable connecting Finland and Germany in the Baltic Sea. The fact that such an incident immediately raises suspicions of intentional damage speaks volumes about the volatility of our times.”