NAIROBI, Kenya (AP) — Kenya police say they have arrested four men on suspicion of attempting to leave the country to join extremist group Islamic State in Libya.

The four men appeared in court in the coastal city of Mombasa Monday where police, through a public prosecutor, asked for authorization to hold the suspects for an additional 30 days, in order to further investigate the men before charging them.

Police say that in the past year at least 20 Kenyans have gone to join the Islamic State in Libya and Middle East.

Authorities fear that the increasing number of Kenyans being recruited by the extremist group is a sign that the Islamic State group is trying to get a foothold in this East African country where its rival al-Qaida already has a presence.