Former Atalanta striker Makinwa drilled just wide in the opening minute, but Rocchi went for glory when he perhaps should have passed to his Nigerian teammate.

Hugo Almeida nodded a Clemens Fritz cross over the bar, but Guglielmo Stendardo should have done better when his weak header from Cristian Ledesma's assist was straight at Tim Wiese.

Rocchi set up Luciano Zauri for a precise angled drive that didn't have quite enough power to beat Wiese's fingertips. Zauri picked up an injury and was forced off the field after just 18 minutes to make way for Under-21 international Lorenzo De Silvestri.

Lazio continued to waste scoring opportunities, Mourad Meghni blasting over from a promising position after good work from Makinwa. The Nigerian went for goal himself soon after, bringing a fantastic reaction save out of Wiese with his shot on the bounce.

Bremen also lost a player to injury, as Frank Baumann clattered into Ledesma, receiving a cut to his head, and was replaced by Daniel Jensen. Emilson Sanchez Cribari did well to clear the danger from a Markus Rosenberg cross.

But Lazio had more of the first half and while Mertesacker's desperate defending managed to close down Rocchi at the last second, Massimo Mutarelli smashed over from the edge of the box.

Rocchi had a fantastic chance on 40 minutes with his splendid volley from Ledesma's corner kick, but defensive bodies charged it down practically on the goalline. Makinwa had penalty appeals waved away.

Lazio took the lead in controversial circumstances after 57 minutes. Naldo shoulder-charged Meghni in the box and the referee awarded a penalty. Although goalkeeper Wiese got a hand to the spot-kick, the ball was at his side when Rocchi came sliding in for the follow-up. Bremen felt the 'keeper had been fouled, but the Croatian official considered the ball to be in play, as Wiese had fumbled it.

The Germans fought back vehemently and Almeida's long-range strike whistled over the bar before 43-year-old Marco Ballotta flew to palm away a rocket of a free kick from Naldo.

Vincenzo Giacobbe, head of police at Arezzo where the incident took place, confirmed that a man had died and did not deny media reports that the fatal bullet had come from a police weapon.

'This is a tragic mistake,' he said. 'Our agent had intervened to prevent the fracas between two groups of people - that had not been considered fans - degenerating into a situation with serious consequences for both groups.

'I express my most profound pain and sincere condolences to the victim's family.'

As news broke of the shooting, the reverberations were felt elsewhere even though Italian Football chiefs, as well as calling off Lazio's game with Internazionale in Milan, initially ordered that the remaining matches kick off 10 minutes later as a mark of respect to Sandri.

Fighting marred the build-up to the Atalanta-Milan game and then referee Massimiliano Saccani took the teams back to the changing rooms after seven minutes of play when Atalanta fans attempting to invade the pitch.

The official decided after a 25-minute wait to call off the game.

AC Milan defender Alessandro Nesta, a member of Italy's World Cup winning squad, said: 'We all came out ready to play.

'Unfortunately, certain episodes happened with Atalanta fans trying to provoke the suspension of the game.

'But the problem is not inside the stadia. The problem is that what happens inside the stadia is a reflection of our society.'

Italian prime minister Romano Prodi expressed his shock over Sunday's events.

Prodi was in church when a government aid informed him that Sandri had died.

Prodi said: 'These are episodes that increase concern.

'I was made aware of the situation by the minister of interior while I was at mass.'

A Lazio spokesman, Giacomo Mazzocchi, said of the incident: 'It's shocking and inexplicable. We are still asking ourselves how could something like this have happened. It's a tragedy.'

FIGC president Giancarlo Abete initially had ruled that all games bar the Inter-Lazio game should go ahead.

Speaking before the abandonment of the Atalanta-Milan game and ahead of the decision to postpone the evening match between Roma and Cagliari, Abete said: 'I would be intellectually dishonest if I said that we had not considered postponing all of today's games.

'But in the end, we believe that we have taken the right decision.

'The incident has yet to be clarified and it should not create any animosity between the fans and the police because what has happened is not yet clear.'

Roma's later request to call off their game with Cagliari was eventually approved with Lazio's city rivals determined not to rub salt into the wounds of their co-tenants at the Olympic stadium.

The club's managing director Rosella Sensi said: 'It is right to ask for the game to be postponed as a sign of solidarity for the Lazio fans and for the city of Roma hit by the death of Gabriele Sandri.'