* Israel blames Iran for attack; Iran denies responsibility
* Bulgaria working with Israel, others to establish identity (Adds details on bombing, comment)
The man who blew up a bus carrying Israeli tourists at a Bulgarian airport, killing himself and six others, was not Bulgarian, the country's interior minister said on Friday.
Israel has accused Iranian-backed Hezbollah militants of carrying out Wednesday's attack at Burgas airport, a popular gateway for tourists visiting the Black Sea coast. Iran has denied having any involvement.
"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."
Investigators said they 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 to pin down who the bomber was in three or four days.
The tourists had arrived in Bulgaria on a charter flight from Israel and were on the bus in the airport car park when the blast tore through the vehicle.