After several exhausting days at sea, more than 600 people have arrived safely in Spain following Italy’s refusal to allow a rescue ship to dock at its ports.

But while the sea ordeal of those on board the MV Aquarius charity rescue vessel might be over, more problems might lie ahead for others attempting to help those crossing the Mediterranean’s rough waters.

Over the past few years, a fleet of mostly volunteer ships has been rescuing people undertaking dangerous journeys daily in their bid to reach Europe from North Africa’s shores.

But the rescuers’ mission to bring to safety those at risk has become even more difficult in recent days.

About a week after saying he would not let Aquarius dock, Matteo Salvin, Italy’s new interior minister and head of the far-right League party, barred two more ships – the Lifeline and the Seefuch – from entering the country’s ports.

Salvini accused the two rescue missions, both of which are run by German organisations, of “being complicit in the illegal immigration business”.

Speaking to Al Jazeera, Alex Steier, one of the cofounders of the Mission Lifeline rescue operation, rejected Salvini’s allegations.

“We deny being involved in some kind of illegal immigration business,” said Steier, adding that the Lifeline rescue mission has always adhered to international laws.

“It’s a populist thing to make these claims. We are doing the job the countries should be doing.”

Twitter spat

The Lifeline has been operating in the Mediterranean since September 2017. At 32 metres long, it can host up to 800 people.

According to Steier, the Lifeline is too small to make the trip from the Libyan coast to Italy with so many people on board. Therefore, those rescued are usually handed over to larger ships heading towards the coast.

“We have rescue equipment to conduct rescue missions. We also have a hospital on board for small surgeries,” said Steier.

“And we have a lawyer on board to make sure we adhere to all laws.”

Following Salvini’s allegations on Twitter, Lifeline responded in a now-deleted tweet saying, “When fascists are advertising us”.

“We have since deleted that tweet and sent out another one in which we stated that Salvini is not a fascist,” Steier said.

La nave Ong Lifeline commenta: “Quando i fascisti ci fanno pubblicità…”.
Roba da matti.
A casa nostra comandiamo noi, la pacchia è STRA-FINITA, chiaro?
Insulti e minacce non ci fermano.
Se voi mi aiutate, io non mollo! #chiudiamoiportipic.twitter.com/w5ZI1H5nYa

— Matteo Salvini (@matteosalvinimi) June 16, 2018

Still, Lifeline’s original tweet led to Salvini calling on the Netherlands to recall the ships, since they both sail under the Dutch flag.

Salvini’s latest decision to bar the two ships might not affect the Lifeline, as it never sails to Italian ports. Yet, it’s a clear indication of the interior minister’s intentions regarding refugees and migrants.

Shortly after the Aquarius reached Valencia, Salvini wrote on Twitter: “For the first time a ship from Libya destined for Italy moors in a different country: a sign that something is changing, we are no longer the doormats of Europe.”

Italy has been the main point of entry for a large number of the hundreds of thousands people attempting to reach Europe via the central Mediterranean route.

Those crossings have resulted in nearly 14,000 deaths over the past four years, according to the Missing Migrant Project.

But closing ports will not deter people from making the perilous crossing, said Ruben Neugebauer, of rescue mission Sea Watch.

“We had more than 900 crossings to Spain just yesterday,” Neugebauer told Al Jazeera on Sunday.

“What we can see now is a shifting of routes as migration is a fact and can not be stopped by fences and walls,” he added.

“People were taken hostage for a political stunt and while the Aquarius was absent people have drowned.”

Neugebauer warned Italy’s stance will have a devastating impact.

“The lack of rescue capacities we face now on the central Mediterranean route will make the journey more dangerous and increase mortality,” he said.

For his part, Steier says the Lifeline ship will continue its mission regardless Salvini’s comments.

“We are saving people’s lives – and to say something negative about that says a lot about a person.”

Al Jazeera has reached out to the Italian and Dutch governments for comment but did not get an answer at the time of publication.