HONOLULU — The total number of people arrested in the deadly explosion of illegal fireworks in a Honolulu neighborhood on New Year’s Eve has grown to 10.

More arrests are expected.

The latest arrests: A man, 32, and a woman 31, were arrested on suspicion of reckless endangering, endangering the welfare of a minor and multiple fireworks offenses. A man, 29, was arrested on suspicion of endangering the welfare of a minor and multiple fireworks offenses. A woman, 28, faces potential charges of endangering the welfare of a minor. Police announced the arrests Friday evening.

The explosion killed three women, one man and a 3-year-old boy and injured about 20 others. It happened when a lit bundle of mortar-style aerials tipped over and shot into crates of unlit fireworks, causing a rapid-fire series of blasts.

Three couples were arrested previously. Police have not said whether those arrested include the parents of the boy, or anyone who was injured.

The igniting of illegal fireworks — many of them aerials normally used in professional fireworks shows — has become increasingly common in Hawaii in recent years. People set off fireworks year-round, ramping up during the year-end holidays, often on cramped residential streets.

Police said last week that they confiscated 500 pounds (227 kilograms) of unused fireworks from the scene of the blast.

Police have been sending the cases to the Honolulu Department of the Prosecuting Attorney.

Police said they are working with prosecutors on the charges but it is taking time due to the number of people arrested, large volume of evidence being examined and fireworks being tested.