Palestinian sources confirmed to Al Jazeera that Israeli forces detained all intelligence staff who were in the building.
The Israeli army said it had sent all those detained for interrogation, claiming it would later release "non-wanted" people.
"The land of Israel belongs to both Jews and Palestinians - as long as there are people who reject this fact, the conflict will never be solved"
Iskander, Boston, US
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Israeli forces have also detained 18 members of the al-Aqsa Martyrs Brigades, part of President Mahmoud Abbas's Fatah faction, and also members of the Palestinian security services, army sources said.
The Israeli army said the 18 were involved in shooting attacks against Israeli civilians and soldiers and in attempts to kidnap Israelis.
An army spokeswoman said: "Israeli forces surrounded the military intelligence building where the men were hiding and called on them to turn themselves in."
"They did so and were arrested and taken away for questioning."
No-one was hurt in the morning raid in Ramallah, which is located in the occupied West Bank, north of Jerusalem.