An arsonist lit up Los Angeles for a fourth straight night, torching more than a dozen targets yesterday in what seemed like a madman’s march to burn down the city, car by car.

Cops said yesterday that the fires are likely the work of more than one Molotov-cocktail-tossing maniac, given how fast and furious cars were igniting.

The arsonist could have an accomplice, or copycats could be at work, anonymous sources told the Los Angeles Times.

More than 40 cars have been set ablaze since Thursday, all parked and empty. The mayhem continued last night, as fire fighters responded to multiple car fires in Hollywood, the Times reported.

“We are dead serious about trying to apprehend the individual or individuals responsible for this,” said county Supervisor Zev Yarslavsky. “We want to get these SOBs before they hurt somebody.”

Early Thursday morning, cops arrested Samuel Arrington for allegedly lighting a fire in a 7-Eleven garbage can, trying to burn up a fuel tank, and another garbage-can fire that resulted in four cars and an apartment building going up in flames in Hollywood, according to the LA Daily News.

Cops also arrested Alejandro Pineda on charges of arson in a garbage-can fire outside a $400,000 home in Los Angeles, said the same report.

Yet new fires raged in rapid succession the next night, leading cops and feds on a frantic manhunt.

Nearly 24 parked cars were torched early Friday morning in Hollywood and adjacent West Hollywood, with flames spreading to some nearby homes — including one formerly lived in by The Doors’ Jim Morrison, which was currently for sale at $1.2 million.

“It was just like a towering inferno,” restaurateur Sandy Gende said .

Yesterday police issued an alert for a man driving either a tan-and-white or cream-colored Lexus.

“We’re pulling out all the stops,” said LA Fire Department spokesperson Brian Humphrey. “We’re hoping that the person or people responsible will be brought to swift and complete justice.”

Panic intensified early yesterday morning, when cars in North Hollywood and the San Fernando Valley exploded in flames.

The damage in West Hollywood alone is estimated at $350,000. Cops have issued a reward of $60,000 for information leading to an arrest and conviction in the case.

Some of the fires had been set in garages and carports, damaging at least four buildings.