Belarus says that Lithuanian border guards on September 28 illegally entered the neighboring country's territory as they tried to detain two Belarusian citizens.
According to Belarus' embassy, the incident occurred at the Lavoriškės-Kotlovka border checkpoint.
"Armed (border guards) crossed the state border of the Republic of Belarus and went around 40 meters deep into its territory. As Belarusian border guard officials were approaching them, the Lithuanians hurried back to Lithuanian territory after the unsuccessful detention operation without giving any explanation," it said in a statement.
The embassy described the Lithuanian border guards' actions as dangerous, noting that the incident occurred at a time of heightened tensions in the region over last month's Russia-Belarus military exercise Zapad.
Border officials of the two countries discussed the incident during a meeting on Friday. Lithuania admitted the violation and apologized, according to the embassy.
The Lithuanian Foreign Ministry confirmed to BNS on Monday evening that it had received the note.
"We confirm that the note has been received. The Interior Ministry and the State Border Guard Service have been asked to provide additional information about the event," Rytis Paulauskas, the Foreign Ministry's spokesman, told BNS.