Kedah police chief Fisol Salleh said the investigation paper into the incident in Padang Terap, Jitra, is being finalised and will then be submitted to the deputy public prosecutor, Berita Harian reported.

This follows the arrest of the father, 30, on Monday. He was released on bail the same day after giving his statement.

The case is being investigated under Section 8 of the Corrosive and Explosive Substances and Offensive Weapons Act 1958 for consorting with a person who carries an offensive weapon, and Section 31(1)(a) of the Child Act 2001 for child neglect.

In the incident last week, two brothers aged four and seven suffered burns after playing with firecrackers in front of their home in Kampung Baru, Padang Terap.

Police previously said the parents were unaware the children were playing with firecrackers, which were believed to be of the ball type and obtained from a friend in the village.

The seven-year-old lost every finger on his left hand while the lower part of his right cheek was torn. His younger brother suffered minor burns on his body and has since been discharged from hospital.