Third-party liability insurance covers damage a drone causes to third parties — people, vehicles, buildings. EU Regulation (EC) 785/2004 sets mandatory minima for aircraft with an MTOM above 20 kg; for lighter drones each member state sets its own rules.
In Latvia the national insurance requirements are published by the CAA. Even where insurance is not mandatory for a given drone, liability cover is strongly recommended for any camera drone — one bad landing on someone else's car can cost more than the drone itself.