TEL AVIV, Israel -- A bomb exploded in a car near a bus in Tel Aviv on Thursday in what police said was a criminally motivated assassination attempt. Four people were slightly injured.

In a country with a long history of bus bombings by Palestinian militants, such explosions immediately cause jitters about terrorism. The explosion went off close to the site of a bus bombing in November.

Israeli media offered various reports of how the blast occurred. Some cited witnesses saying a motorcyclist tossed an explosive device at the car, and other witnesses said the motorcyclist attached a bomb to the vehicle.

Police spokesman Micky Rosenfeld said an investigation was under way and that the target was an underworld figure. He could not confirm the identity of the man targeted.

Israeli media reported that the man was Nissim Alperon, head of one of the country's most powerful crime families.

Alperon has often escaped death. Thursday's attack was the ninth assassination attempt he has survived in the past 12 years.

Just over four years ago, his brother Yaakov Alperon -- known informally as "Don Alperon" -- was killed in a brazen bombing attack in Tel Aviv.

Organized crime, long overshadowed by the Arab-Israeli conflict, has become a part of life in Israel, spawning a "Sopranos"-style TV series. Rival underworld gangs have waged battles for control of gambling and protection rackets.

In the past, rival families would settle their scores quietly. In recent years they have been getting bolder, taking more risks and posing a greater threat to public safety. Most crime bosses travel in armoured vehicles with bodyguards.

Even so, public assassination attempts and bombings by Israeli underworld criminals are relatively rare. The last attempt on Nissim Alperon's life, 18 months ago, was the most recent.