Israeli forces have raided a Palestinian refugee camp in the West Bank, arresting at least 40 people.
The arrests on Monday at the Shuafat camp in annexed east Jerusalem were part of an operation that Israeli police said was aimed at "putting order" in the area.
Al Jazeera's Elias Karram, reporting from the camp, said: "The raid was divided into two parts: the first of which ended on Monday when Israeli army and intelligence forces invaded the came and detained around 40 poeple based on their political affliation - either to Hamas or Fatah.
"The second part is still under way and it targets Palestinian workers who have come from various parts of the West Bank to work in the camps without necessary working permits."
Israeli troops also stormed shops and hospitals in the camp, Karram said.
Rights group targeted
In a separate incident, Israeli military officials raided offices of Stop the Wall, a human-rights group that campaigns against the construction of the West Bank separation barrier.
Stop the Wall released a statement on Monday saying that at least 10 military vehicles invaded the city of Ramallah before officials searched through the offices, "confiscating computer hard disks, laptops, and video cameras along with paper documents, CDs, and video cassettes".
Jamal Jumaa, the co-ordinator of Stop the Wall, said in the statement: "This is part of the continuous targeting of the popular grassroots movement and the struggle of the Palestinian human rights defenders for Israeli accountability.
"Palestinians will not be intimidated by this. The struggle against the Wall will only stop once the decision of the International Court of Justice, which calls for the Wall to be torn down, is implemented."
Jumaa said: "We call on the international community and in particular the European Union to step up pressure on Israel to ensure it respects international law and human rights and ends its repression of Palestinian and international human rights defenders working on the ground."
The raid came after Jumaa was arrested along with Mohammad Othman, a youth co-ordinator from Stop the Wall. Both activists were released on Monday.
In recent months, Israel has intensified its arrest campaign against those involved in the anti-barrier protests. Two pro-Palestinian foreigners were arrested on Sunday.
The activists were employed with the International Solidarity Movement (ISM), one from Spain and the other from Australia.
Israeli forces routinely enter the territory to arrest Palestinians accused of "militant activity".
However, Sunday's raid marks only the second time troops have seized foreigners there on suspicion their visas had expired.
The ISM is involved in protests against the separation barrier.
Omer Shatz, the activists' lawyer, says he believes his clients were targeted because of their political activity.