Bulgarian security forces, Israeli intelligence officers and CIA agents are on the hunt for an accomplice suspected of helping the terrorist who detonated himself near a bus in Burgas last week, killing five Israeli tourists and the Bulgarian bus driver.

Bulgarian police on Saturday distributed a police composite sketch of the suspect to hotels in Burgas and in the surrounding area. The authorities suspect that the accomplice has ties to the Hezbollah terrorist organization.

Bulgarian media reported over the weekend that the suspected accomplice was an American citizen going by the name of David Jepson. One possible scenario is that the explosive device carried by the terrorist, which weighed about 3 kilograms (6.6 pounds), was activated remotely by the accomplice and that the terrorist himself did not know he was going to explode.

According to reports, the accomplice was still in Bulgaria, but this has not been confirmed by the authorities.

Other reports indicated that a Hezbollah cell that was involved in the attack had subsequently fled Bulgaria across the Turkish border.

Meanwhile, the little known Qaidat al-Jihad organization, a branch of al-Qaida, has claimed responsibility for last week's attack in Burgas. Arab media over the weekend ran a statement by the organization, saying, "With Allah's help and accurate preparation, one of our men was able to blow up a bus in Bulgaria carrying Jewish tourists. We will continue to fight Jews and Americans until they get out of Islamic lands."

However, the Bulgarian Foreign Ministry on Saturday rejected the organization's attempt to take responsibility for the attack, echoing assessments by Israel and the U.S. that the attack was carried out by Hezbollah. The New York Times reported last week that U.S. intelligence had confirmed Israeli claims that the terrorist was a member of a Hezbollah cell that was planning to attack Israeli targets in Bulgaria. According to U.S. assessment, the bombing was carried out in retaliation for the assassination of Iranian nuclear scientists.

Bulgarian Interior Minister Tsvetan Tsvetanov briefed reporters over the weekend on developments in the investigation. "In the last 48 hours, large amounts of intelligence were collected," he said, adding that contrary to what Bulgarian media had reported earlier, the terrorist was likely not a Bulgarian citizen. He added that the terrorist spent at least four days in the country before carrying out his attack.

Tsvetanov also noted that Israeli and Bulgarian security authorities were working in tandem on the investigation and that reports that the bomber was previously imprisoned in Guantanamo were untrue. The interior minister also denied reports that Bulgarian authorities received a threat before the bombing that "something terrible will happen soon."

In addition to collaborating with Israeli intelligence agents, Interpol explosives experts from the U.S., France and Switzerland also arrived in Bulgaria to aid in the investigation.

As the investigation advances, Bulgarian authorities continue to reinforce security at the airport in Burgas. Citizens have been prohibited from entering the arrivals area at the airport, where footage showed the terrorist waiting shortly before the attack. In addition, every car entering the airport terminal is being carefully checked.

A few days after the attack in Burgas, life seems to be returning to normal in the Bulgarian coastal city's popular Sunny Beach. Security and safety measures that were bolstered significantly in the 24 hours immediately following the attack have since dwindled. Even in places often crowded with Israelis, only standard security forces were deployed to prevent any disturbances.

With the calming of the storm, many Israelis arrived Friday night at a traditional Shabbat meal at the Habayit restaurant run by the local Chabad House.

Rabbi Chaim Tvardovitz, Chabad's emissary in Burgas, said, "It was important for [Israelis] to come for the blessing, so that everyone knows there is a response to terrorism here and we are not running away."

But not everyone has embraced the calm following the attack. Raz Haham, a young Israeli in Burgas, said, "Until the terrorist attack, no one was scared, but today people are more suspicious and it feels less comfortable to be here. Some people were even afraid to leave their hotels."

Another young woman said she felt as if terror attacks were "chasing" after her.

"Last year, I was in Eilat when there was that terrorist attack there, and two days ago, I couldn't believe it when there was once again an attack near me,” she said. “It's a bit frightening, but I only learned of the attack in Burgas from messages that I received. I felt scared and now I'm just waiting for the flight back to Israel."

Another Israeli tourist said on Saturday that he had to leave his hotel around noon, even though his flight home was at night. The hotel told him he could leave his luggage in its storage room, but he told the receptionist that "the luggage room is not secured, and if I were a terrorist I would take advantage of this." The receptionist was not moved by his comment, and he was asked to leave the hotel room at the agreed time.