TEL AVIV, Israel — Thousands of African migrants, many holding banners demanding freedom for compatriots jailed as illegal job-seekers by Israel, protested on Sunday in a main Tel Aviv square against a new open-ended detention law.

Human rights groups say more than 300 people have been arrested since the law, which allows authorities to detain migrants without valid visas indefinitely, was passed by Israel's parliament three weeks ago.

Some 60,000 migrants, largely from Eritrea and Sudan, have crossed into Israel across a once-porous border with Egypt since 2006, Israeli authorities say.

Many live in poor areas of Tel Aviv and say they want asylum and safe haven. Prime Minister Benjamin Netanyahu has said he views the presence of many of the Africans as a threat to Israel's Jewish social fabric and his government.

An Israeli border fence has since cut off the influx from Egypt, but migrants who have already crossed can be sent to what the government describes as an open prison in Israel's southern desert.

The facility is similar to a half-way house, in which detainees can leave during the day but must report back by nightfall. Migrants can be held there without a time limit pending voluntary repatriation, implementation of deportation orders or resolution of their asylum requests.

Organizers handed out leaflets demanding that Israel "release all refugees from prison and stop this detention policy." Rights groups have appealed the new law.

Police said the protesters had a license for a three-day demonstration at the site, and there was no reported violence or arrests at the scene. A police source estimated the number of protesters at 10,000.

Hotline for Migrant Workers, an organization that advocates for the Africans, accuses Israel of pressuring hundreds in its jails to accept payouts and leave. More than a dozen left earlier this year for Eritrea to win release from prison.