 Russia said on March 3 it would take measures to prevent new border incursions, a day after accusing Ukraine-backed nationalists of killing two people in a cross-border raid in southern Russia. President Vladimir Putin said on Thursday Russia had been hit by a terrorist attack in the southern Bryansk region bordering Ukraine and vowed to crush what he said was a Ukrainian sabotage group that had fired at civilians. A Ukrainian presidential adviser accused Russia of staging the incident as a false provocation to justify aggression against Ukraine. Kremlin spokesman Dmitry Peskov told reporters on Friday that additional measures were being taken to protect the border. Of course, yesterday's terrorist attack will be investigated and measures will be taken to prevent similar events in the future, he said. The FSB security service released video and photos of Thursday's incident showing two shot-up cars with their drivers slumped dead inside.