Israeli arsonists set fire on Monday to an apartment housing Eritrean migrants, spray-painting "get out of the neighbourhood" over the entrance in the latest violence against Africans migrants.
Fleeing poverty, fighting and authoritarian rule, some 60,000 Africans have crossed illegally into Israel through the relatively porous desert border with Egypt in recent years.
Israel says most come seeking work rather than refuge, but this has been challenged by UN humanitarian agencies and civil rights groups, making deportation legally problematic.
The influx has jarred the Jewish state, with its already ethnically fraught population of 7.8 million. Some Israelis warn of a gathering demographic and economic crisis while others say a country born after the Holocaust has a special responsibility to offer foreigners sanctuary.
"Two people were lightly injured from smoke inhalation and were taken to hospital," police spokesman Micky Rosenfeld said, calling the blaze in a Jewish neighbourhood of Jerusalem deliberate.
Israel's Foreign Ministry issued a statement condemning the arson attack, saying "there is no justification for such a heinous crime that endangers people's lives".
Street violence has surged in recent months against Africans, including a rampage 10 days ago in a low-income Tel Aviv neighbourhood which is home to many migrants, from Eritrea, Sudan and South Sudan.
Israeli residents accuse the newcomers of being responsible for rising crime in their areas.
Last week, 11 minors were charged with a string of racially-motivated attacks against Africans in Tel Aviv.
On Sunday, a law went into effect that will allow Israeli authorities to jail illegal immigrants for up to three years. The measure has been denounced by liberal politicians and human rights activists.
But Foreign Minister Avigdor Lieberman said on Monday the migrants were "first and foremost work-seekers" and not political refugees.
"There is talk about these wretched people who walk thousands of kilometres on foot, come here exhausted and in search of political asylum," he said in a speech in the southern resort town of Eilat, where migrants have found work in hotels.
"No one comes thousands of kilometres on foot. They buy a ticket, they fly to Cairo, they come out of the airport in Cairo, they take a bus. There's already an entire industry for transport by bus to the border, to within two kilometres of the (Israeli) border.
"There they get off and are told, 'See those antennas on the hill? Run there.'"