Gaza - Security forces of the Gaza-ruling Islamic Hamas movement held several senior leaders of President Mahmoud Abbas' Fatah party in the Gaza Strip for several hours, senior Fatah leaders said Friday in Gaza.

They said it happened shortly after the group's central committee member Nabil Shaath announced that around 400 Gaza Fatah party congress members could vote for their new leadership by telephone.

Hamas has banned travel of around 400 Gaza Fatah congress members to the first conference in 20 years, saying this was in response to the detaining of around 1,000 Hamas members in West Bank jails.

The 2,500-member Fatah congress, being held in the West Bank town of Bethlehem since Tuesday, is due to elect a new central committee and a new revolutionary council on Saturday.

Gaza Fatah lawmaker Faisal Abu Shahla told reporters in Gaza that among the arrested in Gaza were Ibrahim Abu al-Najja and also Abdullah abu Samhadana, former governor of central Gaza Strip.

Abu Shahla said Hamas had rounded up a number of Fatah officials on Friday afternoon, adding: "We denounced this measure and we held Hamas fully responsible for their safety."

According to Abu Shahla, Hamas security forces had arrested the Fatah officials and held them for questioning for more than four hours.

On Friday, delegates in Bethlehem said they reached a mechanism to enable the Gaza-based members to run and vote in the internal elections Fatah will be holding on the last day of the conference.

A Fatah party news website, "al-Kofia press", claimed Hamas security forces had rounded up most of the Gaza Fatah congress members who were not able to travel to Bethlehem "to prevent them from voting on Saturday."

A comment from Gaza Hamas officials was not available. However, Ihab al-Ghussein, a spokesman for Hamas ministry of interior, said the question of Gaza Fatah members voting by phone "is completely an internal Fatah affair."(dpa)