Palestinian security forces carried out one of the largest waves of arrests in the history of the West Bank following Tuesday's shooting attack near Hebron, in which four Israelis were killed, a Palestinian source said on Wednesday.
According to the source, more than 300 people identified with Hamas have been arrested by Palestinian Authority security forces since the attack.
Hamas' armed wing claimed responsibility for Tuesday's attack, which occurred on the eve of a fresh round of U.S.-backed peace talks.
The Hamas armed wing, the Iz al-Din al-Qassam Brigades, claimed responsibility for the attack from the Gaza Strip.
Palestinian Prime Minister Salam Fayyad vowed to prevent a repeat of such attacks. His Western-backed administration, which is set to resume peace talks with Israel on Thursday, is opposed to violence.
Tuesday's shooting was the most lethal attack on Israelis in the West Bank in four years.
During a visit to a West Bank army base, Defense Minister Ehud Barak said the military will do everything possible to quickly bring the perpetrators to justice. But he urged residents to show restraint.
Barak called on residents to show restraint. "We are in the midst of a long struggle for our right to live in security under a peace agreement with our neighbors," Barak said.
A Palestinian security official, speaking on condition of anonymity under official guidelines, confirmed a crackdown was under way, but gave few details. He said the assailants from the shooting had not been found.
Hamas lawmaker Omar Abdel-Raziq said more than 150 members had been detained, and others had been summoned to police stations for questioning.
He accused Abbas of trying to please the Israelis.
"These are political arrests," he said. "They are trying to tell the Israelis that they are capable of doing the job after the attack."
Abbas, a Western-backed moderate, has carried out frequent crackdowns on Hamas since the Iranian-backed group defeated his forces and overtook Gaza three years ago. In turn, Hamas has frequently targeted members of Abbas' Fatah movement in Gaza.