Wednesday's terror attack is keeping Israelis away from Burgas, Bulgaria, making this week important in determining whether the resort area remains popular among Israelis this summer.

In the suicide bombing, five Israelis and the Bulgarian bus driver died. Before the attack, travel officials had expected about 40,000 Israelis to vacation at the Black Sea resort area.

"The terror attack in Burgas will mean a total halt to new reservations to the destination, which will be booked for other destinations," Zion Madmon, CEO of the TraveList price comparison website, said over the weekend. He said that before the attack, his website had been receiving 40 reservations a day for Burgas. After the news broke, reservations for the area dried up for 24 hours.

Madmon said 70% to 80% of customers contacting the website who had already booked to fly to Burgas wanted to cancel their reservations and go elsewhere. New bookings for vacation packages in general also declined by about 15%, he said.

Israeli charter airlines reported a "minor" number of package cancellations to Mediterranean and European destinations, but no airlines are flying to Burgas at the moment.

A senior executive at Arkia Airlines said most of those calling were asking if they could get a refund if they canceled reservations. "They were also interested in security arrangements at various destinations," he said.

Yehuda Zafrani of the Ophir Tours travel agency said most of his company's cancellations were for near-term travel. "We had 400 to 500 people who were scheduled to travel to Burgas in the near future, and they have asked either to cancel or switch to an alternative destination. Most switched and just a few dozen canceled," he said.

"It's more or less the same as Israelis' [prior] behavior after attacks. There's an impact for 24 to 48 hours and then, to everybody's satisfaction, they return to business as usual."

Another travel industry source said, however, that the coming week will be decisive in determining whether Burgas has a future as an Israeli tourist destination this summer.

"The phase when reservations are switched from Burgas elsewhere will end in the coming week," the source said. "Wholesalers were helped by the fact that they had space for their customers in the Greek islands, where supply exceeded demand, so they could suggest a similar alternative price-wise and for the same type of vacation. When that supply thins out this week, the option of switching destinations will be over."

Wednesday's attack is stinging travel wholesalers and agents who had already transferred funds from clients and must give clients their money back, even if they cannot recoup the funds from Bulgarian tourist sites.

"The wholesalers are trying to minimize the damage," said Ronen Carasso, vice president for marketing at the Issta travel agency. "I estimate that 1,000 to 2,000 people have switched from Burgas to another destination, and that's after we and other wholesalers paid for their hotel stays."

The head of the Israel Tourist and Travel Agents Association, Yossi Fattal, said he thought about 30% of customers scheduled to fly to Burgas from Israel in the near future had switched to other destinations.

"You have to understand that many of the clients going to that destination are young people, and the younger they are, the less sensitive they are to travel warnings," he said. "Travel agents have received many calls from worried parents, not from the young travelers themselves."

Issta is reporting cancellation rates above 30%, however. "Thursday was a bad day. Sixty percent of those who were supposed to go Burgas in the days after the attack asked to change their destinations," Issta's Carasso said.

"Just a few canceled altogether. Most chose to go to Greece and the Costa Brava [in Spain]. By Friday things had stabilized ... and the flow of requests for new destinations, cancellations and questions had nearly ended."

The Daka 90 travel agency said most of its Burgas-bound customers chose to switch destinations rather than cancel outright. "If the hotel and the dates of stay for a new package were the same as those for Burgas, in most cases the customer won't have to pay any more money," said the agency's marketing director, Dana Lavie.

"If it's a more expensive hotel because there was no other substitute, an additional fee will be required. But up to now that hasn't happened."