PATNA: A teenage boy allegedly caught defecating on private farmland was killed on Monday along with his mother in a Bihar village that has been declared 100% open defecation-free. Three other women of the family were critically injured in the clash.Two persons have been arrested, police said.Police said Ranju Devi(50) was attacked with a weapon when she visited the house of siblings Sunil and Sanjay Thakur to accost them for beating up her son. When Ranju’s son Subhash tried to save his mother, he was also assaulted, police officer Indrajeet Paswan said.Four other members of the family — Pana Devi (55), Etbari Thakur (57), Soni Devi (30) and Babli Devi (28) — were allegedly attacked when they intervened. Except Babli, all three are in a critical condition, the police said.Saran SP Har Kishor Rai said two persons, including one of the Thakur brothers, had been arrested and the weapon used in the crime seized. Sunil is absconding.