An explosives-laden motorbike exploded at a police headquarters in Surabaya on Monday, wounding at least 10 people a day after suicide bombers in the city killed 13 people in attacks on several churches.

Authorities said six civilians and four police officers were hurt in the blast.

East Java police spokesman Frans Barung Mangera told The Jakarta Post that investigators believe a similar type of explosive was used in both Monday's attack and the church attacks over the weekend.

The Associated Press reports that surveillance video "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."

As NPR's James Doubek reported earlier , at least five people carried out an attack Sunday on three separate churches in Surabaya. Police say that six members of a single family, including girls aged 9 and 12, set off the series of suicide bombs.

No group immediately claimed responsibility for Monday's attack on the police headquarters on Monday, but the Islamic State said it had directed the attacks on the churches a day earlier.

Indonesia's president condemned Sunday's attacks as "barbaric."

The AP reports that separately, three members of a family were killed in Sidoarjo, a town bordering Surabaya, when homemade bombs in their apartment exploded.

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