According to Times News of Israel, yesterday’s bomber is named Mehdi Ghezali:
Bulgarian media on Thursday named the suicide bomber who blew up a bus full of Israeli tourists, killing five Israelis and a local bus driver, in the Black Sea resort of Burgas on Wednesday as Mehdi Ghezali.
There was no independent confirmation of the veracity of the information. The reports surfaced soon after Israel’s Prime Minister Benjamin Netanyahu had publicly accused Hezbollah, directed by Iran, of responsibility for the bombing. The Prime Minister’s Office made no comment on the reports.
The Weekly Standard reported back in 2009 that Ghezali was picked up in Afghanistan in 2001 and sent to Gitmo and was released in 2004:
In late 2001, Ghezali, a Swedish national, had been detained during the battle at Tora Bora, Afghanistan, handed over to the American military, and sent to the detention facility at Guantánamo Bay. According to his lawyers, he was simply in the wrong place at the wrong time. Although he spoke none of the local languages, Ghezali told his captors, in the midst of the Taliban’s retreat into the mountainous hinterlands of Afghanistan, he had crossed that country’s border with Pakistan to study Islam.
After an intense lobbying effort by Swedish prime minister Göran Persson–and a vague promise that the country’s intelligence services would keep a watchful eye on him–Ghezali was delivered to Sweden (on the government’s private Gulfstream jet). The Swedish daily Dagens Nyheter noted that Ghezali had achieved “rock star status” upon returning to his homeland, a native victim of America’s rapacious imperialism. And after two-plus years in isolation, the emotionally fragile former prisoner would be happy to discover “that a majority of Swedes were glad that he was home.”
According to the article he was also arrested in 2009 in Pakistan carrying an explosives belt. I guess he was released for a second time, the latter by the Pakistanis.