Unknown assailants entered the headquarters of the Palestinian Authority-controlled Civil Administration building in the northern Gaza Strip early Thursday morning, sacking the office, officials said.

The Civil Administration, which in Gaza remains under the control of the West Bank Palestinian Authority government, is charged with coordinating with Israel on matters relating to the crossing terminals. The office targeted by the vandals was in charge of liaising with the Israeli Civil Administration office around the Erez crossing in the northern Strip.

Upon entering the office Thursday morning, officials told Ma'an they were surprised to find the doors pushed in, and entered on a scene of destruction, with desks turned over, computer monitors smashed and mobile phones missing.

The vandalism came hours after leaked documents were shown on satellite television in an Al-Jazeera documentary, showing transcripts of a February 2008 conversation between then Israeli Foreign Minister Tzipi Livni and Palestinian negotiator Ahmed Qurei in which the two discuss the breach by Hamas of a border wall between the Gaza Strip and Egypt.

"Does the opening of the border appear to be a victory for Hamas?" Livni asks.

Qurei replies in the affirmative and asks what Israel intends to do about it. Livni responds that there is no longer an Israeli presence at the site, following its unilateral pullout from the Gaza Strip.

"You reoccupied the West Bank and you can occupy the crossing if you want," Qurei was reported as replying.

It was not the first time the offices had been targeted, however. Six times since the Hamas take-over of Gaza officials in the Civil Administration have reported similar break-ins.

Protests were also reported in the southern Gaza Strip.