Eight people were detained in Nablus, seven in Tulkarem and its suburbs, three south of Hebron and one in Kafr Qaddum, according to the Palestinian WAFA news agency.
In Ramallah, three young Palestinians and three former prisoners were also arrested during raids, while additional operations took place in Jenin and nearby towns.
The arrests come amid a broader Israeli security crackdown following a July 24 settler raid in the village of Tal, southwest of Nablus, that left at least four Palestinians and two Israelis dead.
In response, Israeli forces have intensified operations across the northern West Bank.
As part of that escalation, troops have increased raids in towns, villages and cities and set up checkpoints restricting access to Nablus.
Defense Minister Israel Katz has also instructed the military to prepare to take control of another Palestinian refugee camp following a series of deadly incidents last week, the Israeli news website Ynet reported.
Meanwhile, Israeli military operations, demolitions, settler violence and settlement expansion continue to drive displacement, casualties and property damage, with Bedouin and herding communities in Area C among the hardest hit.
According to the UN Office for the Coordination of Humanitarian Affairs, or OCHA, fatalities linked to settler attacks in 2026 have already surpassed the total for all of 2025.
As of July 20, OCHA said, 18 Palestinians had been killed, compared with 17 during all of last year.
The same reporting period saw about 90 Palestinians displaced by demolitions and settler attacks, many following a large-scale demolition by Israeli authorities in a Bedouin community in Qalqiliya governorate.
These actions have also damaged homes, water systems, schools and other livelihood assets, further limiting access to essential services.
Moreover, OCHA documented in a July 23 report at least 50 settler attacks resulting in casualties or property damage, nearly 60 percent of them in Ramallah and Nablus governorates.
Since the start of 2026, more than 1,330 such incidents have been recorded across 250 Palestinian communities, averaging more than six per day.
Against this backdrop, UN Secretary-General Antonio Guterres reiterated criticism of Israeli settlement policy.
In a statement on Monday, he said settlements in Palestinian territory have “no legal validity” and constitute a “flagrant violation” of international law, as violence escalates and Israel advances plans to legalize outposts and build new ones.