It was the fourth assassination attempt on a man with deadly enemies, and again it failed. But the grenade ricocheted off the car and exploded near Zoran Domini, an innocent passer-by, taking his life as another victim of the gangland wars that now plague the Croatian capital.
Mr Domini, 36, was the second person to die recently in the mafia wars erupting across Zagreb's Habsburg-era tree-lined streets and squares. Beneath the city's veneer of civilisation, and its Austro-Hungarian architectural splendours, rival gangs, many with links to international organised crime, are fighting a deadly turf war for control of gambling and prostitution rackets. The other victim, Damir Dzeba, 30, a Bosnian-born underworld figure, died in a hail of machine-gun bullets in front of a Zagreb cafe last month.
The mob wars have come at a particularly bad time for Croatia. The world's spotlight is on the Croatian capital as the country's authoritarian nationalist President, Franjo Tudjman, lies, possibly dying, in hospital. There is an atmosphere of deep political uncertainty as the battle for the succession is played out in Zagreb's corridors of power.
The prize is high indeed. More than anyone else, the former general with Tito's partisans built up this nation perched on the fault-line dividing mittel-Europa from the Balkans. President Tudjman and his officials repeatedly espoused what they saw as their Western democratic credentials, but, apart from Serbia, nowhere else in the region were the interests of party, state and president welded so seamlessly together.
In a fine display of the government's determination to crack down on organised crime, neatly choreographed both for the television cameras and the electorate who go to the polls on 3 January to choose a new government, Croatian police sealed off border crossings and set up road-blocks as they arrested nine alleged mobsters. Interpol assisted in the investigation as weapons, explosives and forged documents were seized.
High-level security measures were in force as the nine handcuffed suspects were taken from the police headquarters in the centre of town to the courthouse.
Each suspect was flanked by police officers wearing balaclava helmets and flak-jackets, while dozens more officers, armed with AK-47s, sealed off the route - scanning the rooftops for any sign of accomplices who might try to spring them.
Zagreb's police chief, Jakob Bukvic, said those arrested would be charged with conspiring to form a criminal organisation, at least one murder and two attempted murders. The gang's alleged leader was named only as Nikica J, born in 1962.
The arrests of alleged gangsters sent a message to the population that the ship of state was being steered firmly on course. But while the arrests are a blow to organised crime, they will not eradicate its power and influence. There have been at least 22 mafia-style killings in Zagreb since 1991, 20 of which remain unsolved, according to the Croatian press. As in most of the former Yugoslavia, weapons are easy to obtain. Guns and grenade launchers are usually brought in from neighbouring Bosnia, and there is no shortage of former soldiers willing to fight in the mafia wars that have replaced the nationalist conflicts. Many of Zagreb's kingpins of crime fought as soldiers or paramilitaries in Croatia or Bosnia.
Among the nine arrested were suspects believed to be linked to the rocket attack that killed Zoran Domini. The Croatian newspaper Vecernji List said police hoped to solve at least four mafia killings with the arrests, including the murder of Ivan Sokota in 1997. Like Damir Dzeba, Ivan Sokota was killed in front of a Zagreb cafe. Mr Sokota, aged 24, knew he was a marked man, and even wore a bulletproof vest for protection. But that did not save him. His killer, believed to be a professional hitman, shot him through the armpit, where the vest did not reach.
Other mysterious events add to the uneasy atmosphere in Zagreb. Two US citizens recently had their homes broken into, and the US State Department said it suspected the Croatian government may have been involved.
One of the houses was the home of a US diplomat. It was ransacked while she and her children were away, but it appears that nothing was taken. She has since left Croatia, ahead of the scheduled end of her tour of duty. The other incident occurred at the home of a woman representing the National Democratic Institute, a pro-democracy group.