The harrowing story told by immigrants who survived after their boat was rammed by people smugglers may not be the only one of its kind, according to the Prime Minister.

Joseph Muscat said the latest tragedy recounted by immigrants who were brought to Malta last week confirmed that unless anything was done, criminal gangs would continue to act with impunity.

"The stories being told are genuine... But this is only one tragedy that we know of and there may be many more like it," he said this morning when asked for a reaction to the story told by three Palestinian survivors.

In comments to Times of Malta, one of the survivors said he saw traffickers chop off the hands of an immigrant who tried to cling on to their boat.

The tragedy was described as mass murder by migrant organisations. Traffickers forced some 300 migrants to board a smaller boat out at sea and when they refused, the criminals rammed the big boat until it capsized. Only a handful of people survived.

"It is no wonder that the UNHCR and IOM described this as murder," Dr Muscat said, adding the best way to stem the illegal networks was to ensure security and stability returned to Libya.

He reiterated the call for UN intervention in Libya, which did not necessarily mean putting boots on the ground.

"It is important to bring all parties together and any intervention must respect the wishes of the Libyan people," he said.