Around five men armed with rifles and clubs burst into the office of al-Arabiya in Ram Allah late on Saturday, the news organisation said.
They herded the employees into a room and then set about smashing computers and other equipment in the office.
No one was hurt during the incident.
A journalist at the network's news department in Dubai told Aljazeera.net no reason had been given for the attack, but said the assailants had warned the staff in Ram Allah to leave.
The news network could not confirm whether the attackers were really from al-Aqsa Martyrs Brigade.
The journalist said Palestinian police had apologised for the incident and had promised to investigate.
The news organisation would reopen its offices in Ram Allah as soon as possible, he added.
Based in Dubai in the United Arab Emirates, Al-Arabiya is a 24-hour Arabic language satellite broadcaster. Owned by the Middle East Broadcasting Centre (MBC) it began airing in February.