Bulgarian President Rosen Plevneliev has departed for the Burgas Airport where a number of Israeli tourists were killed and wounded in what appears to be a terrorist attack.

Plevneliev has headed to Black Sea city of Burgas from Sofia, the press service of the Bulgarian Presidency announced Wednesday night.

The blast at Bulgaria's Burgas Airport Wednesday night, in which a number of Israeli tourists are reported to have been killed or wounded, is a terrorist attack, according to the Bulgarian police.

Between 3 and 5 Israeli tourists are reported dead and some 18-20 are reported wounded in the explosion which hit their bus at the Sarafovo Airport near Bulgaria's Black Sea city of Burgas at about 5:30 pm EET.

The Bulgarian authorities have confirmed there are casualties have not confirmed their number.

The site of the Burgas Airport says the Israeli tourists arrived on a flight of Air Via from Tel Aviv at 4:50 pm. After that, they got on a bus to reach Bulgaria's largest Black Sea resort Sunny Beach.

According to reports, there were about 40 Israeli tourists on the bus. A total of three buses caught fire on the Burgas Airport parking lot, a local news site, Burgas 24 says.