Bulgarian authorities on Friday released an artist’s sketch of a man believed to have helped the bomber who blew up a bus full of Israeli tourists in Burgas on Wednesday, killing five Israelis and the Bulgarian bus driver.

Bulgarian officials have been quoted in the past two days as saying the suicide bomber was not Bulgarian, but had some local assistance.

The five Israeli fatalities were buried Friday. Seventeen injured Israelis were still in hospital on Friday night.

Bulgarian officials were quoted on Friday as saying they were very close to identifying the bomber, who arrived in the area about five days before the attack, at the local Sarafovo Airport.

The Bulgarian authorities on Thursday released a video clip, filmed on airport security cameras, of the alleged bomber walking around in the airport terminal just before the attack.

Bulgarian prosecutors said the attacker had short hair, not the long hair seen in the security video footage captured of him at the airport. A witness said he appeared to be wearing a wig.

The same man, according to eyewitnesses quoted on Israel’s Channel 2 news, had been seen speaking to tourists at local beaches in the days before the attack.

According to one eyewitness report, the man got talking to a group of tourists from Holland, and told them that his mother was Dutch and his father was Iranian.

Israel’s Prime Minister Benjamin Netanyahu has blamed Hezbollah for carrying out the attack, under the direction of Iran, and pledged a forceful response.

The Bulgarian authorities are being assisted in investigating the blast by teams now in Burgas from Israel’s Mossad external intelligence agency, Shin Bet domestic security agency, and Israel Police, Israeli media reported on Friday.

The Bulgarian news agency Sofia reported Wednesday that the bomber was carrying an American passport and Michigan driver’s license, both believed to be forgeries.

Sofia also reported that the Bulgarian Interior Ministry managed to recover the fingerprints of the bomber, which they submitted to the FBI in the United States and the international police organization Interpol. The FBI and CIA joined Israeli and Bulgarian officials in investigating the attack.

Interior Minister Tsvetan Tsvetanov told Sofia that DNA tests were being run to determine the identity of the Caucasian man, who the minister described as casually dressed with nothing suspicious about his appearance to set him apart from the crowd of people at the airport.

The ministry did not indicate how the police came to the conclusion that the man caught on airport security cameras in the clip was the suicide bomber.

On Thursday, Bulgarian news reports had claimed the Burgas bomber was identified as Mehdi Ghezali, but the reports were not confirmed by officials and were denied by some official sources.