An "explosive device" has been found in a van parked outside Sofia international airport in Bulgaria.
Part of the capital city's airport was evacuated while security services checked bags spotted in the van.
Airport spokeswoman Daniela Veleva confirmed police had found an explosive, and said officers were working to dispose of it safely.
An Afghan man has been shot dead by border guards in Bulgaria, the country's interior ministry said.
The man, who was travelling with a large group of refugees, was shot near the southeastern Bulgarian town of Sredets late on Thursday.
He was taken to hospital but later died.
Georgi Kostov, the chief secretary of Bulgaria's interior ministry, told Bulgarian radio station BNR: "Our border patrol of border guards and police in the area stumbled on 50 offenders, who illegally entered the country.
"They put up resistance during the arrest. One of the officers fired warning shots and, in his words, one of the migrants was wounded by a ricochet and later died."
A British tourist has been reported missing after apparently getting into difficulties during a morning swim in Bulgaria.
Teacher Ethan McKen, 24, was travelling with a group of five friends and had arrived at the Sunny Beach resort on the Black Sea today.
Thomas Cook has been in touch with the family of Mr McKen, from Nottingham, and is arranging for his relatives to fly to Bulgaria.
One other member of the group entered the sea, but is safe and recovering in a local medical centre.
Mr McKen is a member of Bulwell FC, an amateur football club in Nottinghamshire.
We are very concerned by the disappearance of one of our customers in Bulgaria after they took a morning swim in the sea in Sunny Beach resort.
We are liaising closely with the British Embassy and the local authorities as the search effort continues, and can confirm that the local police are stopping anyone entering the water at present while this continues.
The Chancellor George Osborne has insisted the government will continue to fight for Britain and British interests in Europe.
His comments come after reports from Germany that Chancellor Angela Merkel has threatened to withdraw her support for keeping Britain in the EU if David Cameron continued in his drive to curb immigration from other EU countries, in defiance of the EU policy on the free movement of people.
A 22-year-old woman from Wales has died after a night out in a bar at a Bulgarian ski resort, officials have confirmed.
Nina Holmes collapsed outside BJ's bar in the town of Borovets, some 45 miles from the capital Sofoia, on Sunday night.
It has been reported that eight other British nationals were taken to hospital following a night out in the resort, prompting a police investigation.
A spokeswoman for the Foreign and Commonwealth Office confirmed the death of a British national in Bulgaria and said it was providing assistance to the family.
South Wales Police said it was aware of the incident and would be working with Swansea coroner Philip Rogers once Ms Holmes' body was repatriated.
Simultaneous raids in four European countries in the early hours of this morning will "severely disrupt" the drug trade, officers hope.Read the full story ›
The Bulgarian ambassador to the UK called the tone of the immigration debate "very unpleasant".
Konstantin Dimitrov told ITV News Political Correspondent Carl Dinnen, "It is defamatory, definitely there are elements of discrimination."
"This propaganda hurts the pride of many Bulgarians ... the humiliation that such a rhetoric contains is something that may leave a trace here or there in the soul of my compatriots," he added.
As flights and buses arriving today showed, many Romanians and Bulgarians have been living in Britain for years.
But we should also be welcoming new arrivals, just as Britons arriving in France, Spain and other European states find themselves welcomed.
It's time to end the toxic immigration debate and acknowledge that, whether they are nurses and doctors coming to work in the NHS, computer game designers or building workers, Romanians and Bulgarians, as with other immigrants, will be contributing to our society.
Some will settle, some will only be here for a few years, and they reflect the mobile nature of life in the modern world which enriches all of our lives.
Victor Spiresau has arrived in the UK from Romania today in order to find a job in construction, he told ITV News.
The 30-year-old said he earned 10 euros a day working on building sites at home and that he hopes to make 10 euros an hour here, but was not planning on settling.
"I don't want to stay here. I want to renovate my home and to make a good life in Romania because it's much easier to live in Romania because it's not expensive."
Mr Spiresau said he already has work lined up washing cars in London but hopes to go on to work in the construction industry. He said he chose to come to the UK over other European countries as he can speak the language.
There are more British jobs advertised on a Romanian recruitment website than all of the other European countries with similar employment laws combined.
Eight other countries are joining the UK in lifting working restrictions for migrants today - Austria, Belgium, France, Germany, Luxembourg, Malta, Spain and the Netherlands.
The Romanian recruitment website Tjobs.ro carries the following numbers of job advertisements:
- UK - 4,896
- Austria - 245
- Belgium - 25
- France - 591
- Germany - 2,055
- Luxembourg - 50
- Malta - 95
- Spain - 130
- Netherlands - 214