Victim of terrorism, what should I do?

My girlfriend and I live in a fourth floor apartment. Last Friday night our living room window was smashed in by a full beer can. We were sleeping and thought at first that someone had broken into the apartment. We could hear someone shouting like an animal outside in an eastern european language. We are the only Irish couple living on our floor and maybe in the whole building. There are also groups of upto 8 hoodlums walking around the premises and hanging around about the place. The next day we were walking through the building and passed these scary looking foreign guys. One of them started shouting at us in the same foreign language. I don’t know any of these people and have never caused any trouble myself. We are now staying in a guest house down the road and cannot contact the landlord till after the weekend. We are scared and I’m really angry with the landlord for not spending money on decent security for the place. I’m not spending another night in the place but still have to go back to get all my stuff out. I know they’ll want a months notice and I need a reference from them.