A man suspected of carrying out dozens of New Year arson attacks across America's second-largest city that destroyed parked cars and scorched buildings was in custody today.

German national Harry Burkhart, 24, was held in Los Angeles on suspicion of arson of an inhabited dwelling. Authorities said they did not know how long he had been in the United States. .

Burkhart, who told police he was from Frankfurt, was arrested yesterday because he resembled a "person of interest" captured on surveillance video.

He was stopped by a reserve sheriff's deputy in a van being sought by arson investigators, who did not rule out the possibility that others may be involved.

More than 50 blazes have flared since Friday in Hollywood, neighbouring West Hollywood and the San Fernando Valley, causing about £2 million in damage. Firefighters have not responded to any other suspicious fires since Burkhart was detained.

Police declined to reveal any motive for the fires. When asked at a news conference today about reports that an immigration problem with Burhkart's mother may have been a factor, authorities declined to comment.

"We are very confident in this arrest, but we have a long way to go," said Police Chief Charlie Beck, who mentioned receiving information from federal authorities who recognised Burkhart from the video.

They believed he had been involved in removal hearings in immigration court, but they did not specify how he was involved.

Most of the fires began in cars, and authorities have not said how they were started.

The blazes forced many residents from their homes, but there were no serious injuries - one firefighter was hurt in a fall from a ladder, and another person suffered smoke inhalation.

One of Saturday's fires occurred at the Hollywood and Highland entertainment complex, a popular tourist destination bordered by the Walk of Fame in a neighbourhood that includes Grauman's Chinese Theatre.

Damaged buildings included a former home of the late Doors singer Jim Morrison in Laurel Canyon.

The onslaught of intentionally-set fires left residents on edge over the holiday weekend in some of the most densely populated areas of the city. Hundreds of investigators, police officers and firefighters raced to deal with the blazes. Police conducted extra patrols all weekend and the noise of helicopters and sirens persisted virtually non-stop in Hollywood.

Even long-time firefighters struggled to recall an arson outbreak involving so many fires.

Los Angeles County Sheriff's Department Division Chief James Lopez recalled a notorious case from a generation ago, when California arson investigator John Orr was sentenced to life in prison without parole for the 1984 killings of four people in one of multiple fires he set over the course of years.

"Sometimes it's pathological in nature," Mr Lopez said. "I think motives are going to be hard to come by. We may never know."

Investigators were still busy today mapping out the sequence of the blazes, examining more than 100 clues and interviewing witnesses.

Despite the arrest, authorities continued to urge vigilance.

"We're not resting, and we're not stopping" the extra patrols, police commander Andrew Smith said.

"If you have lights in your carport area, keep them on tonight."

Some other deliberately-set fires were reported on Thursday in Hollywood, and two people were arrested. But police said yesterday that those suspects were not connected with the 52 other blazes.