25-year-old Ravi first killed his lover Renu and her landlady Sheila (53) in south-west Delhi's Bindapur. He then travelled more than 40 km to Ghaziabad to eliminate the girl's father Harender and sister Baby to avenge his loss.

Ravi, who was continuing his relationship even after Renu's marriage, was unhappy over her family not allowing him to marry her, a senior police official said.

Renu and Sheila were shot dead at around 9:10 AM in Bindapur. Sheila was killed when she rushed in after hearing the gunshot, which felled Renu.

According to Sheila's property-dealer son Dinesh, he rushed from his nearby office after hearing the gunshots and saw a man running out of his house with two firearms in his hands. Dinesh claimed that the man threatened to shoot him when he came in his way and then fled in a car.

Police said Renu's husband, a cab driver, has gone to Madhya Pradesh. His brother, who was staying with the couple, was also not present.

"At the time of incident, a domestic help was in the house but she became so scared that she could not tell us anything," a senior police official said.

According to doctors, Renu suffered two bullet injuries while Sheila was hit by three bullets.

Ravi then drove to Bhojpur in Uttar Pradesh's Ghaziabad where Renu's family stay. He entered the house and pumped bullets into Harender and Baby killing them on the spot, the official said.