At least 12 people were killed and another 10 seriously injured after a Polish bus overturned and crashed into a ditch on a motorway in eastern Hungary early Sunday, Hungarian Prime Minister Peter Magyar said.The bus was travelling on the M3 motorway when it ran off the road and tipped over near Mezokeresztes, according to Hungary’s state news agency MTI.Magyar announced the casualties in a Facebook post and expressed condolences to the victims’ families.“12 people lost their lives and at least ten were seriously injured during the night when a Polish bus overturned into a ditch on the M3 motorway,” Magyar wrote.He also thanked those involved in the rescue operation.The cause of the crash was not immediately known.Further details about the identities of those killed or injured, and the circumstances leading to the bus leaving the motorway, were not immediately available.