A man has been arrested for setting a house fire which killed three of his relatives and injured two others, days after boasting on TV about how he tried to save them.

Wilber Romero, 26, was arrested on Friday on suspicion of arson.

Police in San Diego say he set a fire at his family home the previous Sunday which killed his father, mother and 21-year-old sister and which put his 24-year-old sister and 17-year-old brother in the hospital.

It remains unclear what his alleged motive was. Last week, he gave interviews claiming that he tried to save them from the blaze.

Wilber Romero, 26, (second right) was arrested on Friday on murder and arson charges for allegedly setting a fire which killed his parents, Jose and Nicolasa (center), his younger sister Iris, 21, (also center) and which put his 24-year-old sister Wendy (far left) and younger brother Angel, who is now 17, (far right) in the hospital

Wilber said in interviews last week that he was sleeping outside when the fire began and that he screamed for help

Many of the details remain unknown, but family friends say Wilber survived because he was sleeping outside at the time.

In an interview with KGTV, he said: 'My dogs were jumping on me, trying to wake me up. I woke up. When I woke up, my bed was on fire.

'I jumped out of bed and started screaming the house is on fire.'

Police have revealed harrowing details of how some of the family tried to escape including how the sister who died, Iris, used her body as a human shield to protect her younger brother Angel.

Wendy banged on a door so hard to try and escape that she broke fingers.

The fire began at around 4.30am at the family's home on October 13.

This was all that remained of the family's home after the October 13 fire. It tore through the building at around 4.30am

Nicolasa, 46, died in the hospital. Iris, 21, used herself as a human shield to protect her younger brother from the flames. She died at the hospital a day after her mother

Wilber's father Jose Antonio Romero, 44, died at the scene.

His 46-year-old mother, Nicolasa, died at the hospital, as did Iris.

Angel and his other sister, Wendy, are expected to recover.

Neighbors said they saw some of the family members poking their fingers through bars in the window to try to escape

Before Wilber was arrested, he attended a vigil for the family where he thanked friends for their well-wishes.

A GoFundMe page was launched by a family friend to help pay for the family's mounting medical bills.

Now, Wilber is charged with three counts of first degree murder, two counts of attempted murder and arson.

He is due in court on October 22.