Officers block a road following an attack at the local police headquarters in Surabaya, East Java, May 14, 2018. The police headquarters in Indonesia's second largest city was attacked Monday by suspected militants who detonated explosives from a motorcycle, a day after suicide bombings at three churches in the city. AP

Officers block the road outside a local police headquarters following an attack in Surabaya, East Java, May 14, 2018. The police headquarters in Indonesia's second largest city was attacked Monday by suspected militants who detonated explosives from a motorcycle, a day after suicide bombings at three churches in the city. AP

Anti-terror policemen stand guard following a bomb blast at a police office in Surabaya, Indonesia May 14, 2018. Surabaya police spokesman Frans Barung Mangera said civilians and police were victims of the attack but didn't immediately announce a death or injury toll. REUTERS/Beawiharta

Anti-terror policemen stand guard following a bomb blast at a police office in Surabaya, Indonesia May 14, 2018. CCTV footage shows a car and two motorcycles approaching a security checkpoint at the police complex followed by an explosion from one of the motorbikes with at least two people aboard it. REUTERS/Beawiharta

Officers stand guard following an attack at the local police headquarters in Surabaya, East Java, May 14, 2018. The police headquarters in Indonesia's second largest city was attacked Monday by suspected militants who detonated explosives from a motorcycle, a day after suicide bombings at three churches in the city. AP

Anti-terror policemen stand guard following a bomb blast at police office in Surabaya, Indonesia May 14, 2018. Four officers, 6 civilians wounded in attack on Surabaya police headquarters. REUTERS/Beawiharta