Israel's domestic security agency, Shin Bet, opposes granting two Jewish right-wing extremists early release from prison.

A Jerusalem court in 2002 sentenced Ofer Gamliel, 52, and Shlomi Dvir, 37 - nicknamed the "Bat Ayin Underground" - to 15 years for a botched attempt to bomb a Palestinian girls' school in east Jerusalem.

A parole board on behalf of the Israel Prison Authority is scheduled to convene Wednesday to decide their fate.

A third member of the group, Yarden Morag, sentenced to a 12- year prison term, was set free earlier this year.

Israeli law provides eligibility for early release from prison based on a clean prison disciplinary record, so long as the inmate had served two-thirds of his term. Security-related offenses, however, are much less tolerable and Shin Bet's recommendations weigh heavily in parole hearings.

Shin Bet chief Yoram Cohen was initially receptive to the claim that the two men no longer present a threat to society, but had only recently changed his mind following consultations with security and legal officials who said that paroling them would serve as an incentive to the country's extremists, the Yediot Aharonot daily reported on Tuesday.

"Shin Bet held a series of discussions with the attorney general and the state prosecutor on the issue of releasing the members of the Bat Ayin Underground," the security agency said in a statement released Tuesday.

"In light of the gravity of their actions and the need to deter others, and as they are completing two-thirds of their incarceration, it is fitting to object to their early release," the statement said.

The prisoners' attorneys said their clients have already " expressed regret" and are hoping to return home and rehabilitate their lives.

If the parole board turns down the request, they will next be eligible for early release in November, according to the report.