Burundi said on Tuesday it had released six juveniles who were part of a group of 11 students jailed last week for allegedly defacing a photograph of President Pierre Nkurunziza in a school text book.
Authorities in the central African country have been cracking down on critics and the opposition against a backdrop of tension and violence sparked by Nkurunziza's decision to run for a third term last year.
Last Friday, police shot and wounded a student and a taxi driver during a protest by schoolchildren against the arrest of their colleagues a day earlier.
Prosecution of the other five students, aged between 18 and 21, would proceed "normally".
In another incident last month, more than 300 students of a school in the capital's Ruziba neighbourhood were sent home after being accused of defacing Nkurunziza's image.
Violence broke out in Burundi last year after Nkurunziza announced he would seek re-election for a third term.
Opponents accused him of violating the constitution, which they said limited him to two five-year terms. The government cited a court ruling which they said cleared him to stand again, and Nkurunziza subsequently won re-election last July.
More than 450 people have been killed in violence between government security forces and various rebel factions opposed to his continued rule. The United Nations estimates the year-long violence has displaced over 250,000 Burundians, who have fled mostly to Tanzania and other neighbouring countries.