Israel's mass round-up of mainly African immigrants had netted a total of 240 people by Tuesday and the interior ministry said that another 300 people had agreed to be repatriated voluntarily.
"Our officers today detained 100 illegal immigrants and another 300 submitted requests to leave voluntarily," a ministry spokesman said.
The arrests bring the total number detained for deportation since Sunday to 240, most of them South Sudanese.
On Sunday, raids saw police round up some 25 immigrants, around a third of them from South Sudan, and the campaign gathered speed on Monday, when 115 people were arrested, many of them in the Red Sea town of Eilat, close to where they crossed into Israel from Egypt.
Those who agree to leave Israel voluntarily will receive free airline tickets and a grant of 1,000 euros ($1,250), but the offer is "only on the table for one week," Population and Migration Authority spokeswoman Sabine Haddad told AFP.
Official figures show there are 60,000 Africans living in Israel illegally, most of whom live in run-down neighbourhoods of south Tel Aviv. Interior Minister Eli Yishai estimates that another 6,000 or so may have slipped into the country undetected.
Around a quarter of the total are living in Eilat, where an AFP correspondent saw immigration police stopping African passers-by and asking for identification.
"For the time being, I feel good. I'm not sure they can find anything on us," said 32-year-old Anthony Christiano from South Sudan.
"I don't blame them (the immigration police) -- it's the state that wants us out," he told AFP.
Nearby, native-born resident Yusef Khuri sat at a small table gathering signatures to urge the authorities to rid the city of its African immigrants, flanked by posters reading: "Free conquered Eilat."
Signup to our newsletter and follow us on Facebook and Twitter!
"They have wrecked our country and have taken over every aspect of our lives," he spat. "They are border jumpers, they should be shot."
Last week, an Israeli court decided that the lives of an estimated 1,500 South Sudanese were no longer at risk in their homeland, clearing the way for their mass expulsion.
It was not immediately clear when the deportations would begin, although a report in Israel's Maariv newspaper suggested that the first flight would leave for Juba, the capital of South Sudan, on Sunday.
The interior minister, who has frequently tried to expel non-Jewish immigrants, sparking accusations of racism, on Tuesday said the raids were "just the beginning."
"At the moment we are permitted only to deport citizens of South Sudan and the Ivory Coast," Yishai wrote in the Israel HaYom newspaper.
"The next stage is the removal from Israel of all the infiltrators from Eritrea and Sudan."
Allowing them to stay would mean "the end of the Zionist dream," he warned.
Rising tensions over the growing number of illegal immigrants entering Israel exploded into violence last month when a protest in south Tel Aviv turned nasty. Demonstrators smashed African-run shops and property, chanting "Blacks out!"
Israel, which reportedly backed South Sudan through its 1983-2005 war with Khartoum, recognised the new nation and established full diplomatic relations with its government shortly after it declared independence in July last year.
The Jewish state does not have relations with Sudan, which it has accused of serving as a base for Islamic militants.