News agencies cited police sources who put the number of demonstrators taking part in Sunday's demonstration at between 10,000 and 30,000.

Some of the protesters, mainly from Eritrea and Sudan, chanted slogans in English such as: "we are all refugees" or "yes to freedom, no to prison" as they marched through Tel Aviv before gathering in Rabin Square in the city center.

This was just the latest in a series of demonstrations by African migrants to protest against a law that came into force last month, which allows the government to detain illegal immigrants for up to a year without trial.

Human rights groups say the government has used the law to arrest more than 300 people since it was passed three weeks ago.

'Open' detention

Several hundred migrants, all of whom entered Israel illegally, are being held at what officials describe as an ‘open' detention facility near Israel's border with Egypt.

The migrants being held there may leave the facility during the day but are not allowed to seek employment. They are also required to report to the authorities several times daily and to return voluntarily within 48 hours or face arrest.

The migrants are kept at the facility in the southern Israeli desert for as long as it takes for the Israeli authorities to decide whether to grant them asylum or to deport them. Israeli officials have also said they offer grants of several hundred dollars to migrants who agree to return home voluntarily.

Many of the more than 60,000 people believed to be living in Israel illegally argue that going home is not an option, as their lives would be in jeopardy if they returned to their countries of origin. Most are believed to have crossed into Israel from Egypt over the last several years, before the construction of a new fence largely closed what was once a porous border area.

The new law, passed on December 10, replaced earlier legislation, which had allowed the authorities to detain migrants for up to three years. That law was struck down by Israel's top court back in September.

The Association for Civil Rights in Israel is among the organizations that have already filed a legal challenge to the new legislation.

pfd/msh (Reuters, AFP, AP)