Semarang – Restraint is being urged after members of Barisan Ansor Serbaguna (Banser), the youth wing of Nahdlatul Ulama, the country's largest Islamic organization, attacked an Islam Defenders Front (FPI) regional head who publicly smeared the group on Sunday.

In a sermon on Sunday early morning, Syihabuddin, head of the FPI chapter for Wonosobo regency in Central Java, reportedly accused Banser of supporting a brothel in Semarang.

After the sermon, about 250 Banser members confronted Syihabuddin in his car, demanding he apologize. When Syihabuddin refused, the Banser members broke the windows, causing minor injuries to the FPI head.

"After the incident, I asked Banser members in Solo, Jepara, Kudus and other regions to stay calm and avoid escalation," Banser Central Java coordinator Ali Mahfud said on Wednesday.