ISTANBUL (AP) — Military school cadets who were arrested following the failed coup in Turkey were unwitting participants because their commanders told them they would be attending a "surprise party" for the new head of the academy, relatives of the youths said Friday.

Standing outside the juvenile detention facility in the Istanbul suburb of Maltepe, families of about 60 cadets called on authorities to release them and put their commanders on trial instead.

The cadets were rounded up after daybreak Saturday from outside the Kuleli Military High School, one of Turkey's largest and most prestigious academies, as the rebellion by a faction of the military fell apart.

The families said they have not been able to see the youths since their arrest, and neither have their lawyers. An official complaint was filed Thursday against the commanders by the relatives.

Nearly 10,000 people have been rounded up since the failed coup on July 15, most of them from the military. Many of those arrested apparently are from the lower ranks, including cadets. Relatives said the many of the teenagers thought they were going to take part in a training exercise.

Lawyers say 62 cadets are accused of attempting to overthrow the government, but no official charge sheet has been released yet.

Their relatives vehemently denied the youths were willing participants in a coup attempt, saying they were summoned to school from vacation by commanders who duped them into taking part in the rebellion and deploying them onto Istanbul's streets.

One 48-year-old father said his son, a first-year student, and others were told to come to school July 15 for the reception. The son called again to say the reception was delayed and a "surprise party" for the new commander was planned, said the man, who asked to be identified only by his first name of Mustafa because he feared government retaliation.

The son later called again and said he was given an unloaded gun and told to wear a camouflage uniform and flak jacket, and stand guard outside the academy, Mustafa said.

When father and son spoke again, images of the coup were being shown on TV, but Mustafa said he didn't want to tell him what was unfolding because he was afraid of adding to his son's agitation.

"They are in no condition to question orders. They are young," Mustafa told The Associated Press. "When they were given empty weapons and were deployed on the streets, they thought they were playing a game of soldiers."

The father added: "A 13- or 14-year-old can't be a traitor."

Dozens of relatives gathered outside the Caglayan justice palace on Wednesday, seeking a glimpse of their detained relatives, mostly conscripts.

Baki, a man in his 30s, said he was looking for his brother, Mehmet, who was on his last day of military service when the coup began. Mehmet had called him on the day of the coup attempt after handing in his weapon, but he was given a new one.

"They told him there will be a field exercise," said Baki, who also spoke on condition his full name not be used for fear of retaliation. "He was waiting to be released. He was a security guard at a parking garage and wanted to get back to that job."

On Saturday, Mehmet called and said he had been detained by authorities, Baki said.

The government has not given any details of trials for the thousands who have been arrested in the week since the coup failed.

At the Maltepe juvenile detention facility, Mehmet Alkanat spoke to reporters about his detained son, Hasan.

"For three days, we have been waiting in front of prison. We can't get any information, and we don't know how his health is," Alkanat said. "Please be aware of this injustice and please resolve it as soon as possible."

Associated Press writer Bram Janssen contributed to this report from Istanbul.