The three escapees were imprisoned by the Palestinian Authority on charges they had planted bombs which killed three US security guards travelling in a convoy in October.
The Popular Resistance Committees helped break the fighters out of prison on Wednesday in defiance of Palestinian Authority President Yasir Arafat, who overruled a high court decision last month to drop charges against the three and release them.
Popular Resistance Committees spokesman abu Abir said on Friday the group helped free the three during a "special" visit.
"Members of the Popular Resistance Committees managed to grab their three members and leave the prison," he said.
The committees accuse Arafat of bowing to US pressure to prosecute the three fighters. A fourth detainee from the Committees remains in solitary confinement.
"The court said clearly the men were to be released and we have just released them," abu Abir said. "We did not break the law, it was an implementation of the law."
There was no comment from the Palestinian Authority on the breakout, but a US diplomat complained it was an indication the Palestinian Authority did not take the process seriously.
Abu Abir said the entire breakout took a matter of minutes and denied comments from a witness that they fought with police during the getaway.
"We did not shoot anybody or towards anybody," he said. "The only shooting that took place was to secure our departure."