MOSCOW (Reuters) – The Kremlin said on Tuesday that the introduction of martial law in Ukraine following Russia’s seizure of three vessels in the Kerch Strait could create tension in Ukraine’s conflict-stricken south-east.

Kiev on Monday imposed martial law for 30 days in parts of the country most vulnerable to an attack from Russia after President Petro Poroshenko warned of the “extremely serious” threat of a land invasion.

“The imposition of martial law in various regions potentially could lead to the threat of an escalation of tension in the conflict region, in the south-east (of Ukraine),” Kremlin spokesman Dmitry Peskov told reporters on a conference call.