(Reuters) - San Diego police on Tuesday were chasing tips pouring in about an apparent serial killer targeting homeless men, officials said, a day after a former suspect was released over a lack of evidence.

San Diego Police Captain Dave Nisleit said no firm leads have yet developed from tips that have come in since the release of 36-year-old Anthony Alexander Padgett on Monday, but police were chasing each one.

"We're getting a ton of (tips) every day," Nisleit said in a phone interview. "We're going to take any tip we receive whether it's inside or outside the city."

Nisleit said police and prosecutors agreed not to charge Padgett and released him on Monday after discovering "exculpatory evidence," though he could become a suspect again if new information pointed in his direction.

Three men have died and another was severely wounded in four attacks this month on homeless men in San Diego that police say appear to be the work of the same person.

The body of the first victim was discovered on fire on July 3 between a highway and train tracks in the Mission Bay area of San Diego, police said.

The following day before dawn, a 61-year-old homeless man was discovered bleeding, with trauma to his upper body, less than 4 miles south of the first attack, police said. He was taken to a hospital in critical condition and is still being treated, according to Nisleit.

Later that same morning, another homeless man was discovered with severe wounds to his upper body and was pronounced dead at the scene near tennis courts in the Ocean Beach neighborhood.

Early last Wednesday, a homeless man was found critically wounded when he was set on fire outside a downtown San Diego apartment building, police said. That victim died of his injuries on Sunday, Nisleit said.

(Reporting by Curtis Skinner in San Francisco; Editing by Sharon Bernstein and Cynthia Osterman)