A Florida judge set bail of US$150,000 for George Zimmerman Friday after he surprised many by taking the stand and apologizing to the family of Trayvon Martin.

Judge Kenneth Lester ruled that Zimmerman can be set free on bail after his family testified that he is not a threat to the community, nor a flight risk.

The family testified by phone, saying they had been threatened and were afraid to venture out into public to attend the hearing.

As per the conditions of his bail Zimmerman cannot possess firearms, drink alcohol or use drugs, and must observe a curfew.

Lester said Zimmerman will not be released Friday and details still need to be worked out between Zimmerman's lawyer and law enforcement. Ahead of the hearing his lawyer said he would be requesting that Zimmerman be allowed to leave the area in order to protect his own safety.

Zimmerman is charged with second-degree murder in the so-called neighbourhood watch shooting death of Trayvon Martin. Zimmerman, 28, maintains he was attacked by Martin and was acting in self-defence.

The incident has enflamed racial tensions in the U.S. after police waited weeks to charge Zimmerman.

On Friday, Zimmerman asked to make a brief statement in court.

After being warned that anything he said could later be used against him, Zimmerman told Martin's parents he was "sorry for the loss of your son."

Wearing a suit and shackles, Zimmerman spoke directly to Martin's parents, rather than to the judge, and said he didn't know their son was only 17 and didn't know whether he was armed at the time of their altercation.

Martin was shot and killed on Feb. 26 as he returned from buying a snack at a local convenience store.