Part of Trakia motorway and a bypass route leading into Burgas will remain closed at least until the afternoon on Saturday as heavy chain-reaction crashes have left the roads jammed since Friday evening.
Travelers are advised against using Trakia motorway after the Zimnitsa junction in eastern Bulgaria.
A 4-km line of vehicles seeking to cross into Turkey has been caused by an operation of security and law enforcement officers, the Bulgarian National Radio reports.
Police have raided administrative spaces and residential buildings in Black Sea city of Burgas and the town of Yambol.
Twenty-eight customs officers have been detained so far, the prosecution says.
A project is being prepared to build a railway between the central area of Burgas, the second-biggest coastal city, and Sarafovo Airport, Bulgarian Transport Minister Ivaylo Moskovski has said.
His words have come during an inspection of an infrastructure project in the area of the maritime station in Burgas.
Police on Saturday detained five Bulgarian nationals near Sliven in the country's east over their alleged involvement in the smuggling of nearly two dozen migrants.
Three cars were stopped by officers for a routine check in the afternoon. Subsequently, twenty-four irregular migrants were found inside the secret compartment of a TIR truck that was officially carrying timber.
The movement Natsionalna saprotiva (National Resistance) has called for a protest march against migrants who have taken over the streets of the capital.
The protest will start at St. Nedelya church on Friday evening. The protesters will pass through streets where migrants have been placed in order to reach Lions' Bridge in Sofia.
Nearly a hundred miners staged on Wednesday a blockade of the road linking Burgas and the resort town of Slanchev Bryag (Sunny Beach) by the Black Sea.
A trade union official representing workers at the mine earlier told the Bulgarian National Radio the average value of salaries and layoff compensations owed to each of them was to the tune of BGN 2000 (around EUR 1023).
Workers at closed Cherno More mine, in the region of Burgas, blocked on Tuesday morning the road between Burgas and the resort of Slanchev Bryag (Sunny Beach) to protest against the delay in payment of wages and compensations.
Work at the mine ended earlier in April, leaving its workforce of nearly 300 people without jobs and with unpaid salaries for March.