The European Union is facing renewed calls from left-wing activists and human rights organisations to revive large-scale search-and-rescue operations in the Mediterranean after the Italian coastguard pulled almost 10,000 migrants from the sea in the past week. Included in that number is a group that claimed Christians had been thrown overboard from their craft before they could be rescued.

“It is time to bring back the search-and-rescue capacity of the Mare Nostrum operation, this time as a collective European effort,” Jan Egeland, secretary general of the Norwegian Refugee Council, told the Guardian.

Operation Mare Nostrum used warships to intercept traffickers’ boats and transfer them to southern Italy, and cost three times more than current operations. It was suspended last year partly in response to British pressure and has been replaced with Operation Triton.

“Operation Triton and Mare Nostrum are two very different operations: the first was run by the Italian navy and was taking place close to Libya. Operation Triton is run by Frontex, whose mandate focuses on border control. This is why our operation takes place closer to the Italian coasts,” said Izabella Cooper, a spokeswoman for Frontex.

Cooper added: “While our primary focus is border control, saving lives is an absolute priority. Since the beginning of 2015 about 18,000 migrants arrived in Italy of which 16,000 were rescued during in search-and-rescue operations. Out of these over 5,000 – a third of the total – were rescued by Frontex vessels in Triton.”

Tragically, more than 900 are feared to have died so far this year, more than in the same period in 2014. The total number of migrants crossing the Med rose from 43,000 in 2013, to a record 170,000 in 2014, according to the UN Refugee Agency. This year is widely expected to be another record year.

Justin Forsyth, chief executive of Save the Children, argued: “Our political leaders cannot ignore the fact that without search and rescue we are allowing thousands of innocent children and their families to drown off the coast of Europe.”

Critics argue that large scale and expensive search-and-rescue operations endanger lives by increasing migrants’ incentives to make for Europe. Rather than opening Europe’s porous southern border further, effectively controlling them would mean migrants and people traffickers (who charge £700 per person) would not chance it in the first place.

Matteo Salvini, MEP and leader of Italian political party the Northern League, wrote on Facebook: “I ask the league’s governors, mayors, assessors and councillors to say no, with every means, to every new arrival.” He was denounced as “inhumane” and “extreme.”

However the number of would-be migrants in Australian immigration detention centres has halved since 2013 when they implemented the radical approach of turning back boats.

As expected, it drew outrage from rights activists. But the message was broadcast that the country is only open to legal immigration and now dangerous and illegal practices have subsided, lives have been saved.