The Pentagon said Friday that there are signs that Hezbollah orchestrated the Wednesday suicide bombing which killed five Israelis in Bulgaria.Top Israeli officials, including Prime Minister Binyamin Netanyahu and Defense Minister Ehud Barak have maintained since immediately after the attack that Hezbollah and Iran were responsible. Pentagon spokesman George Little was quoted as saying by AFP on Friday that while the US was not prepared to say with certainty that the Israeli claims were true, there was evidence to that effect."The attack does bear some of the hallmarks of Hezbollah but we're not in a position to make any final determination on who was responsible," Little stated.Both Iran and Hezbollah have denied any involvement in the attack.Bulgarian investigators said on Friday that they had managed to obtain DNA samples from the fingers of the bomber and were checking databases in an attempt to identify him. Bulgarian Prime Minister Boiko Borisov told parliament he hoped that would be done in 3-4 days.The interior minister added that the man who blew up a bus carrying Israeli tourists at a Bulgarian airport, killing himself and six others, was a foreign national and Sofia was trying to pin down details with the help of foreign spy services."We are talking about a person that is not a Bulgarian citizen," Interior Minister Tsvetan Tsvetanov told a news conference. "We are exchanging information with our Israeli colleagues and the other services." Tsvetanov said investigators were working on several leads, including the possibility that the bomber had an accomplice, but he denied media reports that a local Hezbollah cell was behind the bombing."Such topics, and such interpretations have not been talked about or discussed. At the moment we are focused on realistic options," he said.Channel 2 reported Friday that Bulgarian Police began distributing a sketch of the alleged accomplice in hopes that the public could help them in the investigation.The Israeli tourists had arrived in Bulgaria on a charter flight from Israel and were in the bus in the airport car park when the blast tore through the vehicle.Closed-circuit video showed the bomber wore Bermuda shorts, a blue T-shirt and cap, blending in with other tourists as he roamed the airport for an hour before blowing up the bus.Some analysts believe Iran is trying to avenge the assassinations of several scientists involved in its controversial nuclear program that it blames on Israel and the United States. Israeli diplomats have been targeted in several countries in recent months by bombers who the Jewish state maintained had struck on behalf of Tehran.The Bulgarian blast occurred on the 18th anniversary of a bomb attack on Argentina's main Jewish organization that killed 85 people. Argentina blamed Iran, which denied responsibility. Reuters contributed to this report.