Palestinian Authority forces have arrested at least 120 people, including Hamas members, in the West Bank over the past two days, raising tension between the rival movements.
At least 20 people were arrested on Saturday, Hamas officials said, a day after about 100 members were detained.
Hamas officials told Al Jazeera that the arrest campaign targeted Hamas members, but also academics, students and former detainees.
Journalist Khaldoun Mazloum was among those arrested on Friday. His wife, Ibtihal Mansour, told Al Jazeera that security forces came to their home to take him away shortly after midnight.
"This is not the first time they arrest him. They always present him with charges related to the material he writes for media outlets," Mansour said.
Adnan al-Damiri, the PA security services' spokesman, said the arrests were not related to political activities but were made for security reasons.
"We will not allow that the West Bank disintegrates into carnage and wars just because Hamas wants escalation," he told Al Jazeera.
Hamas controls the Gaza Strip and is a rival of Fatah, the movement headed by Palestinian President Mahmoud Abbas which controls the Palestinian Authority in the West Bank.
Though Abbas formally reconciled with Hamas last year to form a unity government, distrust remains.
Hamas spokesman Sami Abu Zuhri condemned the arrests as a "dangerous escalation which blocks efforts and reconciliation".
"These arrests are part of the security coordination between Israel and the Palestinian Authority," Abu Zuhri said.
An Israeli military spokeswoman said she had no information on the arrests.
Dozens of Hamas supporters protested in Gaza on Saturday morning, calling for the release of the detainees from PA-run prisons.
Source: Al Jazeera and agencies