Indonesian police officers secure the area following a bomb blast at Surabaya's police headquarters in Surabaya, East Java, Indonesia, on May 14, 2018. Four suicide bombing attackers were killed, four policemen and six civilians wounded in an attack at the police headquarters in Surabaya, provincial capital of East Java in Indonesia, on Monday, a police officer said. (Xinhua/Kurniawan)

JAKARTA, May 14 (Xinhua) -- Four suicide bombing attackers were killed, four policemen and six civilians wounded in an attack at the police headquarters in Surabaya, provincial capital of East Java in Indonesia, on Monday, a police officer said.

The explosion took place at 08:50 a.m. Jakarta time when the policemen were conducting registration check on two persons, one of them a woman, riding a motorcycle and trying to enter the police office compound, provincial police spokesman Senior Commissioner Frans Barung Mangera said.

The spokesman said that the rider of the motorcycle was along with two fellows who were riding on another motorcycle.

Separately in Jedong village of Sukodono sub-district in the province, an anti-terror squad was involved in an exchange of fires with militants. One person was shot and six bombs were seized.

The police arrested two men and one woman, based on a photo display.

The explosion at the police headquarters happened after suicide bombings in three churches and an explosion in a flat in the city a day earlier, killing at least 14 people and wounding dozens others.