Bulgaria on Friday expelled a visiting delegation from the Palestinian group Hamas, the head of the organisation that invited the lawmakers to the EU-member state told AFP.
Bulgarian security service agents "entered the hotel rooms of the three deputies early on Friday morning and drove them to the airport," said Mohd Abuasi of the Centre for Middle East Studies.
"The agents explained to them that they had to leave because of strong political pressure on Bulgaria from Israel," he said, adding that they had departed for Istanbul.
Interior Minister Tsvetan Tsvetanov said in televised remarks that the lawmakers had left Bulgaria, without specifying if they had been expelled.
"These people came to Bulgaria with visas, but since their entry into Bulgaria, they have given different reasons for coming compared to what they had said," he said.
Hamas, which rules in the Palestinian enclave Gaza, denounced the deputies' expulsion.
Hamas "denounces such behaviour which reflects the extent ... of Zionist pressure," spokesman Taher al-Nunu said in Gaza City.
The European Union, like the United States, considers Hamas a terror group and deals only with its rival, the Palestinian Authority.
The trip comes in the wake of a February 5 announcement by Sofia the Lebanese Hezbollah -- like Hamas an enemy of Israel with strong ties to Iran -- was behind a July bombing in Bulgaria that killed five Israeli tourists and their local driver.
On Thursday, Sofia distanced itself from the visit, with the foreign ministry saying the delegation would not be meeting government representatives.
"Our contacts with the Palestinian Authority are direct and pass through the government in Ramallah and the Palestinian embassy in Sofia," the ministry said.
The ministry said a representative had met the Palestinian envoy to Sofia, Ahmed Mohamed al-Madbuh, and underlined that Bulgaria "maintains no contact with Hamas, which is on the EU's list of terrorist organisations".
The three Hamas lawmakers had arrived on Wednesday and were due to participate on Friday in a conference organised by the centre.
This was the first time that a Hamas delegation was staying in a EU country since the Palestinian extremist organisation has been placed on the list of "terrorist organizations".
Previously, a Hamas delegation had visited Switzerland at the invitation of the Inter-Parliamentary Union, despite the protests of Israel.