Describing his son as "a guest among brothers of ours in Syria Islamic State", the father of a Jordanian pilot seized by Islamic State militants in Syria has renewed a plea for his release urging his "hosts" to "treat him well". Youssef al-Kasaesbeh father of the pilot Moaz al-Kasaesbeh's father issued his first plea saying: "I direct a message to our generous brothers of the Islamic State in Syria to host my son... with generous hospitality." Lt Moaz al-Kasaesbeh was captured after his jet crashed in north-eastern Syria on Wednesday during a bombing mission. It is still unclear what caused his plane to crash near the IS stronghold of Raqqa. In a statement issued on Wednesday, the Jordanian military said it held IS and its supporters "responsible for the safety of the pilot and his life".