LONDON - The number of migrants crossing the Mediterranean to Europe continued to fall last month, and the European Union says its policies to ease the crisis are working.

On the so-called central Mediterranean route from North Africa, arrivals were down by a third. And Europe claimed success in slowing the arrival of migrants.

But Amnesty International claims the bloc’s collaboration with Libyan groups involved in the detention of migrants makes it complicit in gross human rights abuses.

Maria Serrano of Amnesty International says this has come at a terrible human cost.

“Europe has decided to cooperate with Libyan authorities, knowing the kind of torture, abuses, detention that migrants and refugees are exposed to in Libya,” she said.

A woman displays her hand with the message "Stop s A woman displays her hand with the message "Stop slavery" as she attends a protest against slavery in Libya outside the Libyan Embassy in Paris, France, Nov. 24, 2017. A woman displays her hand with the message "Stop slavery" as she attends a protest against slavery in Libya outside the Libyan Embassy in Paris, France, Nov. 24, 2017.

?Apparent slave market

In November video emerged apparently showing migrants being sold at a slave market in Libya, prompting international outrage and calls for urgent action from the Donald Tusk, president of the European Council.

“Let me repeat my call to impose U.N. sanctions on human smugglers and traffickers,” he said.

European countries are providing tens of millions of dollars and training to the Libyan coast guard and armed groups under the control of the Tripoli unity government.

That makes Europe complicit in the abuse, says Amnesty’s Serrano.

“They are sent to official detention centers, then militias and other armed groups and Libyan officials control these centers. So, this is a source of money for them. Migrants are extorted, they are forced to call their families, and their families are listening to the awful abuses they suffer, so they receive beatings, they are tortured, women are raped.”

The European Union has funded emergency repatriation flights to take migrants stranded in Libya back to their home countries. But there appears to be little political willingness to soften Europe’s stance.

EU leaders have trumpeted the falling migrant numbers as a way of countering anti-migrant populist forces, says political analyst Leopold Traugott of Open Europe.

“The repercussions of the recent influx in 2016 and 2015 are still felt in most European countries,” he said. “So, until the EU decides and implements a new reform of its migration policies and is able to deliver sustainable solutions, the migrant crisis will still be an issue for European countries.”

FILE - Migrants attend a lesson at the "institute FILE - Migrants attend a lesson at the "institute for intercultural communication" in Berlin, Germany, April 13, 2016. FILE - Migrants attend a lesson at the "institute for intercultural communication" in Berlin, Germany, April 13, 2016.

In 2015, Germany took in more than a million migrants. The backlash boosted support for the far right and cost Chancellor Angela Merkel votes at the September election.

But supporters say her ultimate victory is proof that Germany, and Europe, can successfully integrate the migrants.

Nevertheless, the European Union appears determined to close the routes across the Mediterranean. Despite the risk of torture, abuse and drowning, more than 160,000 migrants made the journey in 2017.