Russian authorities raided the Moscow headquarters of opposition politician Alexei Navalny on Thursday, using power tools to gain entry before dragging Navalny out by force and confiscating technical equipment such as laptops.

Navalny and his allies said the raid on his Anti-Corruption Foundation (FBK) was carried out by the Federal Bailiffs Service and was connected to his refusal to delete a video investigation that leveled graft allegations against Prime Minister Dmitry Medvedev and billionaire businessman Alisher Usmanov.

The Federal Bailiffs Service told Reuters it was carrying out investigative activities at Navalny's foundation as part of a criminal investigation. It said it had not detained anyone during the raid.