A man convicted of terrorism has escaped a high-security prison in Indonesia after disguising himself as a woman by wearing a burqa, AFP reports.

According to police, Roki Aprisdianto put on the full-length Muslim garment and walked out of prison with a group of other burqa-clad visitors. The prisoner had been serving a six-year sentence for masterminding a series of bombings targeting churches, mosques and police stations in Central Java between 2009 and 2011, Jakarta Globe reports. The Islamic militant group had failed to launch any successful attacks.

Four members of the elite anti-terror squad and seven police officers were guarding the prison at the time of the jailbreak. Police said they will tighten security and check burqa-clad visitors before they leave the facility, which holds around 70 terror convicts.

“In the future, besides deploying more police personnel, we will ask visitors to lift up the veil covering their face as they leave the facility,” police spokesman Rikwanto told AFP.

National Police spokesman Insp. Gen. Suhardi Alyus said that they will also deploy female officers at the facility.