Police in Israel have detained about 200 Africans in Tel Aviv following the announcement of tough measures against illegal immigrants.
There are believed to be more than 100,000 illegal immigrants in Israel
A police spokesman said the detainees - mainly from Sudan, Eritrea and the Ivory Coast - who do not have refugee status would be deported.
Human rights activists have criticised the detentions.
Tens of thousands of immigrants, mainly from African countries, are said to be in Israel without permits.
In recent years, many have entered Israel by crossing its long and porous border with Egypt in the south.
Many of the migrants are from Sudan, refugees from the civil war and the crisis in Darfur.
The bulk of the detentions took place on Monday near the old bus station in Tel Aviv, Israel's commercial centre, where immigrants had been sheltering in squalid conditions.
Sigal Rozen, of the Hotline for Migrant Workers in Tel Aviv, said authorities were moving some of those arrested to a prison in southern Israel.
Israeli government statistics show there are about 100,000 legal foreign workers in Israel.
Estimates suggest that at least 100,000 others work in Israel without permits.
Israel recently granted temporary residency status to 600 refugees from Darfur. It also recognised that the lives of about 2,000 migrants from Eritrea would be endangered if they were sent home.
Crossing the border from Egypt is often treacherous. Egyptian border forces have killed two migrants, and shot and wounded two others trying to enter Israel in recent days.
Israeli Prime Minister Ehud Olmert on Sunday instructed Israeli police to deport thousands of African asylum seekers who have entered Israel though the Egyptian border.
He also ordered security officials to tighten control of the border with Egypt.