Why Liverpool fans face danger in Rome... Roma ultras run riot in the capital

Liverpool fans planning to travel to their Champions League semi-final second leg against Roma will arrive in a city struggling to contain their most violent and extreme football supporters.

Tuesday evening's first leg was marred by ugly scenes and fan violence outside Anfield before kick-off that left one 53-year-old Liverpool supporter fighting for his life. Two Roma fans have since been charged with violent disorder.

And the 5000 Liverpool fans who have purchased tickets for the return leg could find themselves in danger when they visit an Italian capital with a comprehensive history of football violence.

Lazio were traditionally Rome's far-right team with a history of fascist associations. Sections of their supporters sung fascist chants during a reading of Anne Frank's diary in October as Serie A's attempts to stamp out anti-Semitism backfired.

But while the politics of Roma has been historically more left-leaning, a section of ultras slowly became more and more infiltrated by right-wing factions during the 1990s.

The move to the right has seen extremist groups resort to violence and supporters of seven different English clubs have fallen victim to attacks from Roma supporters since the turn of the century.

Leeds. Liverpool, Middlesbrough, Manchester United, Tottenham and Chelsea fans have all been attacked by supporters associated with Roma while a host of other European sides and domestic rivals have suffered similar fates on visits to Rome.

One incident just four years ago saw a Napoli supporter shot to death by a Roma ultra before the 2014 Coppa Italia final at the Stadio Olimpico. The ultra was Daniele De Santis, a 48-year-old involved in fascist far-right political groups.

Roma supporters would later chant De Santis' name and unveil a banner mocking the victim's mother at their next game against Napoli, resulting in Roma being fined £10,000 by Serie A.

In response Roma president James Pallotta branded the club's ultras 'f***ing idiots' and 'a**holes' and insisted the majority of fans were tired of such incidents.

But while police are stepping up their clampdown on the more politicised section of the Giallorossi's support, they are struggling to stifle those without political affiliations due to it being harder to gather information on them and prevent attacks.

The incident involving Liverpool fan Sean Cox on Tuesday was characteristic of an attack by supporters without any ties to political groups - poorly organised, unplanned and directly outside the stadium.

The club itself has long attempted to disassociate itself with their ultras which have also overseen more light-hearted incidents, including barricading Roma's training ground with 50kg worth of carrots to accuse the squad of being 'rabbits'.

Roma icon Francesco Totti was forced to meet repeatedly with ultras following runs of poor results in order to reassure them the team would get back on track.

In 2004 a group of Roma ultras even caused the cancellation of the Derby della Capitale clash with Lazio when both sets of fans protested against the authorities after hearing false rumours that a boy had been killed outside by a police car.

Totti was seen attempting to calm down the riotous supporters who were ordering him not to play and the Roma skipper eventually relented, famously telling his manager Cesare Prandelli: 'If we play, they're going to kill us'.

And Liverpool supporters should be particularly wary ahead of the Stadio Olimpico trip given the two clubs' infamous meeting in the 1984 European Cup final.

After Liverpool shocked the heavy favourites Roma by beating them on a penalty shootout at their own ground, Italian supporters spilled onto the streets and began attacking opposition fans at random with knives. One Liverpool fan, George Sharp, almost died from his injuries.

The shameful scenes preceded the infamous Heysel disaster the following year when 39 Italian supporters were crushed before the start of the 1985 European Cup final between Juventus and Liverpool.

As Kenny Dalglish insists the damage done to the relationship between English and Italian supporters in Roma in 1984 resulted in Heysel in 1985, quoted by The Times as saying: 'Without Rome, Heysel would have been different.'

The two teams would later meet in the UEFA Cup and Champions League in consecutive seasons between 2001 and 2002 - which saw more than 20 knife attacks over the course of the four matches.

It all culminates in a potentially dangerous atmosphere for Liverpool fans ahead of the semi-final second leg, who should be wary of visiting Rome given the history of violent incidents between the two clubs.