Coimbatore: A 40-year-old man was killed by his 70-year-old father here at Lingappachetty Street on Monday evening.

The accused, P Muthu of Thoothukudi district, killed his son by smashing his head with a grinding stone and then surrendered before the police.

Muthu, a widower, runs a grocery on Balija Naidu Street and has been living with his son Ganeshan and 38-year-old daughter Radha, who were both unmarried, said the police.

The police added that Ganeshan had turned violent recently, attacking his father and sister, which led Muthu to take him to the Coimbatore Medical College and Hospital. “Doctors asked him to admit his son to the hospital. Ganeshan refused” the police said.

Muthu took Ganeshan home, but smashed his head when in a fit of violence he tried to attack him.