A Palestinian militant group's chilling declaration of war on buses — long a symbol of Israeli grit — struck fear in the hearts of many Israelis. 

The surreal and now hauntingly familiar sight of a shattered city bus lying on its side, the top and roof peeled away and body bags lined up nearby, underscores the vulnerability of a well-established transit system. 

Hamas, the militant group that carried out a bus bombing that claimed 19 victims this week, announced in a leaflet Wednesday that dozens more suicide bombers are waiting to attack civilians in a "war on the buses." 

Tuesday's attack in Jerusalem was the 70th bombing since the latest round of violence broke out in September 2000. Of those, nine targeted buses, killing 70 passengers. 

Bus driver Rahamim Tzidkiyahu, 51, died instantly Tuesday when the bomber blew himself up just after climbing aboard. Since the attack, many drivers have been hesitant to come to work, driver Uri Baruch said Wednesday as he drove Tzidkiyahu's route. 

"When you leave in the morning, you don't know when you're coming back or if you're coming back at all," he said. 

In Israel's early days, nearly everyone relied on buses to get around, and they became a potent symbol of the country's pioneering spirit — even though the most frequent riders these days are students, immigrants and the elderly. 

Buses have played prominent roles in the many wars Israel has fought during its 54-year history. They were mobilized along with reserve soldiers, who found themselves riding to battle by bus. Many buses were abandoned in the desert sands after ferrying soldiers to the Egyptian front in the 1973 war. 

During the two-year war that followed the establishment of Israel in 1948, the fledgling army used buses to try to break a siege of Jerusalem by Arab armies. The first ones to try the journey were shot up by snipers. So commanders outfitted them for combat. 

"My father was a maintenance man who built the armor plates for the buses during the war," said Arieh Caspi, a social commentator who writes for the Israeli daily Haaretz

The attempt failed, however. Most of the buses were stopped by gunfire. Some of the bullet-riddled hulks have been preserved as a memorial at the side of the main highway leading to Jerusalem. 

The use of buses in Israel has changed over the years, Caspi notes. Now most Israelis prefer to drive their own cars, even if it means standing in traffic jams for hours at a time. 

Looking over the lists of victims of bus attacks, Caspi said, "usually they are new immigrants, older women, sometimes children — among the weakest sectors of society. The percentage of elderly people is usually quite high." 

Though riding the bus may not be part of every Israeli's day, an attack on a bus "affects the national mood. It's a very effective target for terror attacks," Caspi said. 

Officials with the Egged bus cooperative report a significant drop in the number of local bus passengers during nearly 21 months of violence. For bus drivers, it's been a particularly harrowing time. 

"I see a lone man standing at a bus stop at a particular time in a particular way," said Baruch, "and though I must not say this and must not think it, I find myself with such mixed-up feelings that I'm even prepared to break the rules," and refuse to pick him up. 

It's a blow to the image of a bus company that made driving a bus a prestigious profession in Israel. Membership in the Egged cooperative meant financial security — enviable in the money-strapped first decades of Israel's history. A common joke equated doctor, lawyer and bus driver as the professions mothers wished for their sons. 

Now safety concerns outweigh the benefits as Egged officials struggle with security problems. New central bus stations, like the one in Jerusalem that opened several months ago, feature security guards who check everyone who enters. 

But there are too many streetside bus stops to be guarded, and the cost of putting guards on all of Egged's 4,000 buses would be prohibitive, officials say.