HELSINKI (Reuters) – Finland is watching its territorial waters very closely following explosions of two Nord Stream gas pipelines, Prime Minister Sanna Marin said on Wednesday. Marin told reporters that Finland, which shares the European Union’s longest land border with Russia, considers the explosions “grave news” and “extremely worrying”. The pipelines were built by Russia and European partners. The European Union on Wednesday promised a “robust” response to any intentional disruption of its energy infrastructure after saying it suspected sabotage was behind gas leaks under the Baltic Sea. …