"There have been reports of people, for example, taking photographs of military and strategic objects, which may be infrastructural, important objects," he told reporters on Wednesday. "This is being monitored and there have been cases when people were detained for doing that."
He did not specify how many such persons were currently detained.
According to Anusauskas, the increase in intelligence activities has to do with Russia's aggression in Ukraine and the movement of troops.
"Of course, there is an increase in activity as when Belarus and Russia withdrew a large part of their forces and threw everything near Ukraine, and the Russians threw everything into Ukraine, they undoubtedly intensified their intelligence by looking at what the situation is like in our country," the minister said.
"I just want to underline that such actions, when military forces are significantly weakened near Lithuania's border, show that NATO countries have never posed and do not pose any threat to them", he said.
The State Security Department announced on Wednesday that Russian and Belarusian intelligence services are targeting opposition activists from these countries operating in Lithuania. They are following them, listening to their conversations and organizing provocations.