Soldiers raided Balata refugee camp in Nablus and arrested four people, locals said. The men were identified as Ahmad and Yazan al-Khateen, Ameed Reyad Saqer, and Mujahed Nazeeh Abu Seris.
One other man, Mujahed Kamal Abu al-Hayat, was arrested in the west of Nablus.
An Israeli army spokeswoman said eight people were detained in Nablus, two in Tulkarem and one in Ramallah.
Palestinians living in the occupied territories are routinely arrested by Israeli forces, usually on the pretext of security.
Around 40 percent of Palestinian men living in the occupied territories have been detained by Israel at some point in their lives.