India, May 26 -- A new maritime security incident involving a Turkey-bound gas carrier has intensified concerns over escalating sabotage threats targeting Russian energy infrastructure, after Moscow claimed it thwarted an alleged terrorist attack on an LNG vessel preparing to depart for Turkey from the Baltic Sea port of Ust-Luga.

Russia's Federal Security Service, the FSB, announced Monday that explosives resembling naval magnetic mines were discovered attached to the hull of the Arrhenius gas carrier shortly before it was scheduled to load cargo for onward shipment to Turkey. The vessel had reportedly arrived from Belgium and was expected to continue toward the Turkish port of Samsun.

Turkish authorities responded cautiously to the R...