An Italian bishop has urged women in the Calabrian village of San Luca to help end a feud between two families believed to be linked to six murders.
Police have released an image of the suspected getaway driver
Bishop Giancarlo Bregantini urged the women to become bearers of "forgiveness and peace," according to comments in Corriere della Sera daily newspaper.
The bullet-ridden bodies of the victims were found near an Italian restaurant in the German city of Duisburg.
The event has been linked to a feud between clans of the Calabrian Mafia.
The six victims, all males aged between 16 and 39, were shot as they left the Italian restaurant in the early hours of Wednesday after a birthday party.
St Valentine's Day trigger
Police said the men were linked to the notoriously violent 'Ndrangheta Mafia.
The San Luca feud began with a brawl in the village on St Valentine's Day (14 February) in 1991 and has since claimed some 15 lives.
Italian Interior Minister Giuliano Amato said one of the victims was thought to be one of those originally involved in the San Luca dispute.
"Honoured Society", based in Calabria region of south Italy
Origins thought to date back to shortly after Italian unification in 1861
Group grew as reaction to richer class from north
Operates clan-based power structure based on blood families
Accused of cocaine and weapons smuggling
Estimated to have made 16m euros (£10.8m) in 2002
In his appeal to the women living in the village of San Luca, which is home to 4,000 people, Bishop Bregantini said that "women carry in their hearts forgiveness or vengeance".
German police investigating the murders, who are being assisted by Italian detectives, have released a photofit of a man believed to have been the driver of the getaway car.
Police say the suspect is about 5'9" (180cm) tall, with short black hair, long sideburns and a mole under his right eye.
Witnesses reported seeing two men running from the scene before escaping in a dark sedan car driven by the third man.
On Thursday, Italian police searched about 50 homes in the southern village of San Luca and set up road blocks around the Calabria region.
"We need to deploy units so we can avoid a repetition of these acts," said Francesco Gratteri, the head of Calabria's anti-Mafia unit.
The killings may have been retaliation for the murder last 25 December of the wife of the head of one of the rival 'Ndrangheta families, Italian police said.
Italy's Deputy Interior Minister Marco Minniti said the apparent score-settling in a foreign country was "unprecedented" and "an element of great concern".
"This feud marks a second chapter outside the territory where these clans usually operate - this time even outside our national borders," he told a news conference in Rome.