Police arrested 13 people and more than 170 were injured when the match erupted into a pitched battle between police and fans.

Police denied the rumor but rioting broke out in the stands with some supporters setting fire to the seats and raining flares and bottles down upon lines of riot forces.

Police responded by firing tear gas, while outside the stadium fans set up barricades in the streets and fought a running battle that newspapers said lasted around six hours.

"It was true guerrilla warfare," one police source said.

Some 155 police officers were wounded, one with stab wounds, and 21 fans were hurt, Rome officials said.

The second half of the match was four minutes old, with the score at 0-0, when a fan walked on to the playing area behind the Roma goal to interrupt the match with the rumor of the death.

Both sets of players gathered in the centre circle to discuss the situation with referee Roberto Rosetti as flares rained down on riot police positioned underneath the south stand, where the majority of Roma's supporters were sitting.

The police department of Rome quickly denied the rumor via the stadium announcer.

After a 15-minute delay - during which tear gas and then smoke billowed into the stadium through the exits in the south stand - the match was abandoned.

After consulting with the players the referee Roberto Rosetti stopped the game for the sake of public order.

Officials feared for the safety of the 65,000 fans inside the ground as many spectators tried to escape the choking effects of tear gas which had been used to quell trouble outside the ground.

The police denied the rumor that a boy was killed after being run over by one of their patrol cars.

"No one was run over, no one died," city council spokesman Maurizio Improta, told Sky television.

One eyewitness report suggested a boy overcome by tear gas fell to the floor just as a police van was hurtling by and was later collected by an ambulance.

Some fans close to the scene are said to have drawn their own conclusions and used it as an excuse to go on the rampage.

Italian football league president Adriano Galliani, who is also vice-president of league leaders AC Milan, said he advised Rosetti to suspend play.

"I took the decision because I was convinced that the conditions had made it impossible to play on," he said.

"I spoke to many people on the pitch and I chose the safest option. Certainly, it was a difficult decision.

"I talked to Rosetti, but also with [Roma coach Fabio] Capello and [Roma director Franco] Baldini.

"I asked what truly happened and that the local council told me that reports of a young boy's death were false.

"I told the referee to suspend that match and the game will definitely be replayed.

"Why did I decide to call the match off? I had two choices and I went with the one that my conscience was telling me to go for."

Roma are second in Serie A, 10 points behind leaders Milan, while Lazio are fourth and chasing a place in next season's Champions League.

Earlier Sunday, Inter Milan ended a six-match winless run to keep alive their hopes of a top four finish.

A 2-0 victory over bottom club Ancona was Inter's first league win since February 1 and lifted Alberto Zaccheroni's underachieving team into sixth place on 40 points.

Inter's mercurial Uruguayan international Alvaro Recoba broke the deadlock in the 61st minute with a powerful left-footed strike before providing the cross for Daniele Adani to head home the second nine minutes later.

Zaccheroni said three much-needed points was the perfect tonic as Inter prepare for Thursday's crunch UEFA Cup fourth round, second leg tie against Benfica. The tie is locked at 0-0 after the first match.

"Against Benfica, I want to have players out there who are up for it," he said.

"We badly needed a win to lift our confidence and we showed plenty of character against a team, who despite their position in the table, are difficult opponents."

Zacchroni played down the omission of star striker Christian Vieri, who was a non-playing substitute.

"He was not happy but that is the kind of reaction you want to see from a player," he said.

"Christian wants to play in every game, but I wanted to keep him fresh for Thursday."

Perugia showed they have the stomach for a relegation scrap with a narrow away win at in-form Lecce, their third victory in five matches.

Franco Brienza and Marco Di Loreto scored for the visitors before Wilfred Dalmat's late goal ensued a nervy finale for the Umbrian club, who held on to triumph 2-1 in Puglia.

Siena's status in the top flight still remains under threat despite earning a 1-1 draw at Chievo, while Bologna would appear to be out of danger after thrashing Brescia 3-0.

Ancona remain rooted to the bottom on seven points with Perugia on 22, Empoli on 23 and Modena on 25. Reggina, Lecce and Siena are all tied on 27 points.