About 330 Palestinians have been detained by Israel since the start of the Muslim month of Ramadan 20 days ago, the Palestinian Prisoners' Center for Studies has said.
Since 6 June, when the Muslim month of fasting began, Israel has stepped up its raids on Palestinian towns, the centre's director, Osama Shaheen, told Al Jazeera.
"We noticed that the campaign of arrests against leaders and activists in Hebron has increased, especially due to the recent attack in Tel Aviv," Shaheen said, referring to the 9 June shooting of four Israelis by Palestinians.
Of the 330 detained, at least 60 are children, the youngest being 10-year-old Marwan Sharabati from Hebron. Twenty-one women are amongst those arrested.
About 15 Palestinians, 13 of whom are fishermen from Gaza, were also detained at Israel's Ashdod port.
The raids have been taking place across occupied East Jerusalem, Hebron, Nablus, Ramallah, Jenin and Gaza.
"We are used to this. It is painful, but it has become a routine. There is not one house that hasn't been raided and not one family that doesn't have a martyr."
Israeli prison authorities were not available for comment.