JAKARTA, Indonesia — A wave of deadly bombings on Sunday and Monday and evidence of more planned have shaken Indonesia just ahead of the holy month of Ramadan, with entire families — including children — carrying out suicide attacks against Christian worshipers and the police.

The troubling discovery Monday of completed bombs in a housing complex outside Surabaya, Indonesia’s second-largest city, came a day after members of a single family carried out three attacks against separate churches in the city around Mass time, killing seven people.

On Sunday night, three members of another family, including a child, were killed when a bomb exploded at their apartment outside Surabaya when the police moved in to arrest them.

And on Monday morning, a family of five riding on two motorbikes detonated a bomb at the entrance of the Surabaya Police Headquarters — killing all but one of them and injuring four police officers. An 8-year-old girl who was with the attackers survived the blast and was taken to the hospital.