The Federal Security Service, or FSB, has detected an increase in "foreign disruptive actions" since the souring of relations with the West over the situation in Crimea, a senior FSB official said Friday.
The fate of Crimea, a predominantly ethnic Russian region that seceded from Ukraine and joined Russia last week, has triggered the worst East-West standoff since the Cold War.
"There has been a sharp increase in foreign threats to the state. The legal desire of the Crimean people and those in the eastern regions of Ukraine to join Russia evokes hysteria on the part of the United States and its allies," said Alexander Malevany, the FSB's counterterrorism director, at a meeting with President Vladimir Putin.
"They are undertaking measures to disrupt the social, political and economic life of our country," Malevany added. "In such circumstances, we are planning and implementing active counterintelligence and intelligence measures against their ambitions."
He told the president that Russians, including those in Crimea, are duly protected against radicals and extremists.