On Friday, Lukashenko told a support rally at a state farm that "the US is planning and directing everything, and the Europeans are playing up to it."
Belarusian authorities detained a leader of striking factory workers and summoned prominent opposition activists for questioning on Friday as they try to quash the protest movement against President Alexander Lukashenko.
It comes after opposition leader Sviatlana Tsikhanouskaya urged factory workers to continue striking against Lukashenko's 26-year-rule in a video statement released on Friday.
Speaking from exile in Lithuania, where she fled to be with her family after Belarus' presidential election earlier this month, she said the strikes were a "powerful weapon" to enact change.
"The strikes are an absolutely legal and powerful weapon against the regime," she told supporters. "They know that, and due to that, they want to intimidate you. Leave the fear to the dictatorship. Remember that you are not alone. The whole of Belarus is with you."
"You scared the dictatorship, it is trembling with fear in front of you," she added. “We will force the authorities who holed up in their palaces to hear our voice.”
The country's Prosecutor General announced on Thursday that it has opened a criminal inquiry against the members of the Coordination Council — a body created by the opposition following the election they denounced as rigged to transfer power. They are being investigated on charges of undermining national security.
"The creation and the activities of the Coordination Council are aimed at seizing power and inflicting damage to the national security," said Prosecutor General Alexander Konyuk.
A day earlier, Lukashenko had branded his opponents "Western puppets" and warned strike participants that they would face dismissal in a bid to stop the spreading unrest. On Friday, he told a support rally at a state farm that "the US is planning and directing everything, and the Europeans are playing up to it."
But protesters continued to flock to the street of capital Minsk and other major cities. They reject the official results of the August 9 presidential election which credited Lukashenko with more than 80 per cent of the vote.
Early Friday, police deployed to block the streets around the headquarters of the Investigative Committee where the opposition activists were to be questioned. Several dozen demonstrators rallied nearby to protest the authorities' actions.
A factory worker at the Minsk Automobile Plant also claimed that "hundreds of KGB operatives came to factories to question and scare the workers."
"We are calling for dialogue, but the authorities are responding with threats and new repression," the 53-year-old engineer said.
The EU condemned the criminal probe into the Coordination Council on Friday, saying in a statement that the "Belarusian state authorities have once again reverted to politically motivated intimidation."
The bloc announced earlier this week following a special summit of the EU Council that it would "shortly" impose sanctions against "a substantial number of individuals responsible for violence, repressions and the falsification of election results".
Council President Charles Michel and Commission chief Ursula von der Leyen also reiterated that the bloc rejects the results of the presidential ballot as it had been "neither free nor fair" and once more condemned the "disproportionate and unacceptable violence" against protesters.
On Friday, the foreign minister of Estonia, Urmas Reinsalu and his Latvian counterpart, Edgars Rinkevics, outlining their intention to impose joint sanctions on Belarus, adding it welcomed the EU decision to target individual Belarusian officials involved in electoral fraud and violence against protesters.
In a joint statement, they said: "Estonia and Latvia have prepared the lists of Belarussian officials. Sanctions will envisage visa ban. Bilateral action of introducing sanctions on a national level will take place ahead of upcoming European Union sanctions in accordance with national procedures.
"Estonia and Latvia value very highly the basic principles of democracy among which rights of citizens to express their political will through free and fair elections belong to most important democratic fundamentals. Estonia and Latvia highly value observance of political rights and democratic standards throughout the world."
They added: "Estonia and Latvia will continue to work actively towards strengthening support for Belarusian civic society. Belarus is and will remain an important neighbour and Estonia and Latvia will continue to maintain friendly neighbourly relations with the people of Belarus."
Defence ministers add their condemnation
The German, French and British defence ministers met in Dillingen, Germany on Friday.
Speaking to the media after their meeting German Defence Minister Annegret Kramp Karrenbauer said the group condemned violence against anti-government demonstrators in Belarus.
She added "we don't recognise the outcome" of the recent presidential election that handed President Alexander Lukashenko a sixth term, which she said was "not free or fair".
British Defence Minister Ben Wallace said that "an aggressive Russia" was currently challenging "many of our values" - and that NATO provided the best defence against this.
At least three protesters have died and police detained almost 7,000 people and injured hundreds during the four days of protest.