A court later released six of the youth, who are minors, said lawyer Eric Batunwanayo, who is assisting them.
The youths, aged 14 to 19, were charged with insulting the head of state, a crime punishable by imprisonment of between six months to five years, plus up to $32 in fines, the governor of Muramvya province Emmanuel Niyungeko said.
"Justice must prevail," he said. "After God came the king. Today we have no kings; it is the president who replaced them. So he is in the second position of honor after God. These children made a serious offense. We will keep consulting judicial authorities and parents in order to find a solution."
"Our children never come with books at home ... How can they know exactly those who made the squiggles?" said Nijimbere. "No witness has forward to say they have seen my daughter doing that ... They should all be released immediately."
Last year Nkurunziza won a third term in office that critics say is unconstitutional and has caused turmoil in Burundi that the U.N. Says has resulted in more than 400 deaths.