An hour-long gun battle raged at a psychiatric hospital in the West Bank town of Bethlehem early Thursday before Israeli forces arrested 12 Palestinians, sources on both sides said.
Eight of the 12 were members of the Al-Aqsa Martyrs Brigades Palestinian security sources said.
Among those detained was the Brigades commander for the region, Jamal Hamamrha, who is suspected of involvement in a suicide attack on a bus in Jerusalem on January 29 in which 10 people were killed, as well as the bomber.
The other four were members of the hospital's staff, they added.
A military source said that the 12 were all wanted for their suspected involvement in preparing attacks in Israel. They had taken refuge in the hospital's administrative wing, he added.
Witnesses said that around a dozen military vehicles had surrounded the hospital at the start of the operation.
The Israeli source said that troops had first urged the men to surrender but they responded by opening fire.
The exchanges lasted for around an hour before the group gave themselves up, he added. There were no injuries.
Meanwhile, Palestinian security sources said that four members of another radical faction, Islamic Jihad, were arrested by Israeli troops near the northern West Bank town of Jenin.
The four were detained in a house in Kafr Rai, south-west of Jenin, after around 20 jeeps entered the village at daybreak. Gunfire was heard but there were no reports of injuries.