A Muslim youth allegedly scorned by the family of his Hindu ex-girlfriend was on Thursday charged with murder in the deaths of her father and sister and the severe beating of her mother in southern California.

Iftekhar Murtaza, who had told friends he planned to marry his girlfriend, 18-year-old Shayona Dhanak, was arrested on May 26 at the Phoenix airport with a one-way ticket to Bangladesh.

He is charged with the murders of Jayprakash Dhanak, 56, and his 20-year-old daughter, Karishma Dhanak, whose charred bodies were found on May 22 after firefighters put out a blaze along a bike trail. A day before Leela Dhanak, 53, was found beaten outside the family's burning home in Anaheim Hills.

A neighbour of the Dhanaks told police he or she saw at least two men attacking Leela Dhanak, but Murtaza is the only suspect arrested so far. The search continues for at least one other culprit, police said.

If convicted, Murtaza could face the death penalty or life in prison without parole.

Murtaza and Dhanak, who had met at a party and dated for about three years, had repeatedly broken up and reunited with the latest fallout coming a few weeks before the string of crimes, the Los Angeles Times reported today.

The arrest warrant for Murtaza suggested that a clash of religions led to his break-up with Shayona Dhanak, who was in college dormitory when her family was attacked, the paper reported.

Records show that Murtaza's cellphone had been used near one of the crime scenes an hour or so before the slayings, although Murtaza told authorities he was not in Anaheim on the day of the house fire.

Soon after police interviewed him, Murtaza left for Arizona, where he was arrested on a fugitive warrant at Sky Harbor International Airport in Phoenix.

Court documents said he was carrying a one-way ticket to Bangladesh; his attorney said it was round-trip and that Murtaza had planned to visit his ailing grandmother, the paper said.

"Iftekhar is not guilty," said the attorney, Jeremy Phillips of Phoenix, after Murtaza's May 31 extradition hearing.