Government says protesters are 'economic migrants' – they won't be deported, but may be sent to a desert detention centre

Thousands of asylum-seekers who entered Israel illegally from Sudan and Eritrea have staged protests outside UN offices and foreign embassies in Tel Aviv, accusing Israel of neglecting its responsibilities under the 1951 UN Convention on Refugees. At the same time, supporters held parallel protests at Israeli embassies in 12 capitals, including London, Washington and Paris.

"We left our homeland and our beloved families because of intimidation, persecution and genocide," said Filmon Rezene, 26, who said he risked death if he returned to his native Eritrea. Rezene escaped in a jailbreak six years ago after he was imprisoned for questioning the military's role in his university studies. Three years ago, he was smuggled into Israel over the border with Egypt, across the Sinai desert after a long journey via Ethiopia, Sudan and Libya.

"We are demanding that the UN Human Rights Commission and the international community intervene to stop Israel arresting asylum seekers in the street and make sure there is transparent and fair processing of our requests for refugee status," he said.

The migrants are protesting against Israel's refusal to grant them refugee status and the opening of 'Holot', the new detention facility in the country's south. Photograph: Abir Sultan/EPA

More than 50,000 asylum seekers from Africa have arrived in Israel in the past decade, creating a political problem for the government and causing social tensions with local residents in south Tel Aviv where many of them live. Unable to obtain legal work permits, they eke out an existence in dead-end jobs and live in fear of arrest by Israeli immigration officials.

Populist Israeli politicians have seized on the issue, with one member of parliament branding the migrants a cancer and calling for their immediate deportation. After lengthy delays processing asylum applications – some 1,800 have been submitted and none have been approved – the migrants declared a strike two weeks ago and started demonstrating in an effort to pressure Israel into allowing them to stay.

In a rare public comment earlier this month, Israel's prime minister, Binyamin Netanyahu, dismissed their protests. "These are not refugees, but people who are breaking the law and whom we will deal with to the fullest extent of the law," Netanyahu told cabinet ministers.

The migrants said they had higher hopes of compassion from Israel, a country that has previously absorbed successive waves of refugees.

But the Israeli government says that while it will not force any of the migrants to return to Eritrea or Sudan against their will, it does not want them to stay either.

The migrants, primarily from Eritrea and Sudan, marched from downtown Tel Aviv to the embassies. Photograph: Jack Guez/AFP/Getty Images

"Israel has never considered itself open to immigration on a broad scale [other than the special arrangements for Jewish immigrants]," said Daniel Solomon, legal adviser to Israel's population and immigration authority. "We see most of this group as illegal economic migrants."

Solomon said no one would be forced to leave, but long-term illegal immigrants could be required to live in a desert detention centre for up to a year under a new immigration law that came into force in January 2012. Since the law was passed and a fence was constructed, largely sealing Israel's border on the desert, the amount of migrants has dwindled from 2,000 a month to single figures.

Solomon said 2,500 migrants – including 2,000 Eritreans and Sudanese – had left Israel "of their own free will" during 2013 and a further 500 this month alone, spurred on by a $3,500 (£2,100) grant to each from the Israeli government. Solomon said Israel was close to implementing an arrangement with a third African country that had agreed to accept thousands of the migrants.

But a crowd of several hundred protesting outside the British embassy on the Tel Aviv seafront on Wednesday disagreed. Some had their mouths taped to symbolise the refusal of Israel to hear their arguments.

"85% of Eritreans and 75% of Sudanese are recognised as refugees by most western countries. Only in Israel are we branded economic migrants," said Rezene.