COPENHAGEN, Denmark (AP) — A foreign fighter from Denmark has been jailed in pre-trial custody for 27 days, a day after the man was deported from Turkey, which has begun to send home people who fought for the Islamic State group.

Prosecutor Sidsel Klixbull told the Copenhagen City Court on Tuesday that it was "a very serious case." Ahmad Salem el-Haj was held on preliminary charges of violating Danish terror laws.

He denies the charges. He was arrested upon arrival at the Copenhagen airport late Monday.

Copenhagen police say Denmark in 2017 had asked Turkey for his extradition but in vain. Danish officials also said el-Haj had been found guilty in Turkey and sentenced to four years in prison for joining the Islamic State group.

No date for his trial was immediately announced.