New Delhi, Nov 23 (IANS) Five people were arrested Sunday for stabbing to death an 80-year-old man and critically injuring his wife when they resisted a robbery in their south Delhi home early this month, the police said.

Acting on a tip-off, the police arrested Raj Kumar along with four of his accomplices from Badarpur border.

They had murdered M.M. Gulati and injured his wife Indra Prabha Nov 3, a police official said.

Raj Kumar, a resident of Mathura Road in Delhi, has a number of criminal cases against him, the official said.

The elderly couple was alone at their Sukhdev Vihar residence when the incident took place.

The five armed men entered the house by jumping over the boundary wall and repeatedly attacked the couple with a knife when they resisted the robbery bid. The assailants decamped with Rs.20,000 in cash.