The workers want Lukashenko to give way to Sviatlana Tsikhanouskaya, the leading opposition candidate in the election.
“Lukashenko is a former president. He needs to go,” said Sergei Dylevsky, the leader of the protest at the Minsk Tractor Plant, adding that Tsikhanouskaya is "our president, legitimate and elected by the people”.
Dylevsky voiced concern that the iron-fisted leader's weekend telephone calls with Russian President Vladimir Putin could herald an attempt by the country's giant eastern neighbor to send in troops to prop up Lukashenko.
“We don't want that, and we won't let that happen,” he said.
Lukashenko spoke twice with Putin over the weekend and reported the Russian leader told him Moscow stands ready to provide support in the face of what he described as foreign aggression.
He claimed that NATO nations are beefing up military forces on the border with Belarus — a claim the alliance rejected.
Lithuanian officials pointed at a military exercise Belarus abruptly launched near the borders with Lithuania and Poland on Monday and warned about worrying signs that Russia might be planning to use the situation to take over Belarus.
“If they consider just incorporating the country in a simple way, the consequences would be unpredictable," Lithuanian Foreign Minister Linas Linkevicius said.
Alexander Klaskovsky, an independent Minsk-based political analyst, said the conversations with Putin may reflect the Kremlin mulling support for Lukashenko in exchange for his consent for a closer union between the two nations, which he had resisted in the past.
“Russia understands Lukashenko's weakness and is preparing its own scenario, which could envisage a deep integration in exchange for military assistance,” Klaskovsky said.
The official results of the election gave Lukashenko 80 percent of the votes and Tsikhanouskaya only 10 percent, but the opposition claimed the outcome was falsified.
Tsikhanouskaya has cited reports from precincts around the country showed her winning 60-70 percent of the vote.
The 37-year-old former teacher left for neighboring Lithuania on August 11 under what her associates described as pressure from law enforcement officials.
Her husband, an opposition blogger, has been jailed since May, and she had replaced him on the ballot.
In a video statement released Monday, Tsikhanouskaya said she was prepared to step in as president.