Human Rights Watch said on Monday that the EU's border agency Frontex is facilitating the forced return of sea migrants to Libya rather than their rescue by NGOs or other vessels that would take them to Europe.
Sending back migrants to Libya, where it is known that they face "atrocious treatment", makes Frontex "complicit in the abuse", Judith Sunderland, HRW's associate Europe and Central Asia director, said in a statement.
Frontex called the report's accusations "simply wrong."
HRW released a joint report with Border Forensics, an investigative group, saying it supports "the conclusion that the EU border agency's approach is designed not to rescue people in distress but to prevent them from reaching EU territory."
"More aerial surveillance by Frontex in the central Mediterranean tends to result in more at sea interceptions by the Libyan coast guard," the groups said, speaking of "a moderate and statistically significant correlation."
HRW and Border Forensics cited the example of July 30, 2021, saying the day's flight-tracking data suggested a Frontex drone had spotted at least two migrant boats that were later intercepted by the Libyan coast guard.
An NGO boat, the Sea-Watch 3, was also in the vicinity of the migrant boats but did not receive any messages from Frontex. It witnessed one of the Libyan interceptions "by chance", HRW and Border Forensics said.
In a statement to Reuters, Frontex said it was legally obliged to alert "all the national rescue centres" in the central Mediterranean - including in Libya - whenever one of its planes or vessels spots a boat in distress.
Frontex said it liaises with "all rescue coordination centres in the region: Italy, Malta, Libya and Tunisia. Unlike what the (report) states, all four are internationally recognised rescue centres," it said.
The EU agency added that it was "proud that our crews have helped to save over 300,000 people at sea in recent years."
Migration has for years been a political hot potato in Europe, with governments resorting to increasingly hard-line policies to try to stem the inflow of migrants and asylum-seekers from North Africa and the Middle East.
Over the weekend, Italy took in two NGO rescue ships carrying more than 500 migrants, amid renewed calls from its right-wing government for more EU-wide burden sharing on migration and asylum.
(Reporting by Alvise Armellini, Editing by Hugh Lawson)
