OAKLAND PARK: Two Florida brothers charged with plotting to support terrorists are caring family men who enjoyed living in the US and would never hurt anyone, their family said Saturday.    

Authorities swarmed a quiet, lakefront condominium near Fort Lauderdale earlier this week and arrested Sheheryar Alam Qazi, 30, and 20-year-old Raees Alam Qazi, charging them with plotting to provide material support to terrorists and to use a weapon of mass destruction.

Prosecutors said the two are naturalised US citizens originally from Pakistan. They remained jailed Saturday without bond.

Two people who identified themselves as the men's mother and brother told The Associated Press outside their condominium that one of the jailed men is married. They repeatedly refused to disclose their full names to an AP reporter.

''It's just a whole misunderstanding. A family like this with a baby like this would never do anything like this,'' the brother said. He was reluctant to talk, worrying ''a lot of people don't know what's true'' and stressing that his family has strong values.

''Always love people, always try to help people, if your car breaks down I will help you,'' he said.

Both referred to a 1-year-old boy who lived in the condo with them and missed the brothers who were arrested. However, it was not clear how the child was related to the two jailed men.

The mother said her sons' arrest has been hard on the family, saying ''the wife is crying'' all the time. But she said she was hopeful and repeated that her sons liked living in America.

''This is good America, good state, good job,'' she said. She spoke little English and said she and her husband did not have jobs.

Federal authorities said the investigation was still very active. But they offered few details about the plot, and information was scant in the three-page grand jury indictment released Friday. Authorities said the case was not an FBI undercover sting operation but declined further comment.

The indictment alleges that the two provided money, property, lodging, communications equipment and other support for a conspiracy to obtain a weapon of mass destruction between July 2011 and this week.

It wasn't clear whether the conspirators actually did obtain explosives or what their potential targets might have been.

The brothers' arrest shocked residents in the community, where about a dozen two-story apartment complexes surround a pool and fitness center.

Several residents walked their dogs along the tree-lined street Saturday, and a handful of children played outside.

Neighbors said residents of the apartment complex had to submit to a detailed background check before moving in. The entrance has a security gate with a guard house and video surveillance around the pool clubhouse.

Neighbor Martica Albu, who has lived in the complex for about seven years, said the brothers seemed nice and always greeted her warmly, but said she didn't know them well.

''It's terrifying. It's right here, right where you're living in your condo complex,'' 41-year-old Lano Tice said as he was taking out the trash.

The Qazi brothers had initial court appearances Friday, but court-appointed attorneys for the two did not respond to emails seeking comment.

An arraignment and bail hearing is scheduled for Dec 7.

They could face up to 15 years in prison on the conspiracy charge and up to life in prison on the weapon of mass destruction charge.

South Florida has seen several high-profile terrorism cases, including the conviction of al Qaeda operative Jose Padilla. Five men accused of plotting to join forces with al Qaeda to destroy a landmark Chicago skyscraper and bomb FBI offices in several cities also were convicted in Florida.

More recently, a Miami Muslim cleric and one of his sons are facing trial on charges they provided thousands of dollars to the Pakistani Taliban terrorist organisation.