MOSCOW (Reuters) - Belarusian leader Alexander Lukashenko partially closed the country’s land borders and replaced his interior minister and named three security hawks to new roles on Thursday in an attempt to tighten his grip after months of mass protests.Minsk announced restrictions at its borders with Poland, Latvia, Lithuania and Ukraine, citing the COVID-19 pandemic. Poland said only Belarusian citizens and trucks were being allowed to travel to Belarus at some of its border. Lukashenko has been at loggerheads with his European Union neighbours since the country plunged into turmoil following a disputed election in August. He has threatened border closures before but not acted on the threat. Cars going into Belarus were barred from entry from 1400 GMT, and in few hours the border was closed for outgoing cars, Rustamas Liubajevas, chief of the Lithuanian border guard, told Reuters. The change came without an advance warning, he added. Lukashenko’s government also announced that Ivan Kubrakov, who as head of police in the capital Minsk has led the crackdown on the biggest demonstrations, was appointed interior minister. His predecessor, Yuri Karayev, was one of three men named to new roles as presidential aides and inspectors responsible for key regions of the country. Lukashenko’s position appears more secure after a national strike call by the opposition failed to bring the economy to a halt this week. But Sviatlana Tsikhanouskaya, his main opponent who fled into exile after the election and called for the strike, said the president’s actions were a sign of weakness. “The regime destroys itself. Both the closure of the borders and the next appointments are signals of a weakening of his power. He makes inconsistent decisions because he is in a panic,” she said in a statement. Security forces have arrested more than 16,000 people since a presidential election on Aug. 9 which the opposition and Western governments say was rigged. “Lukashenko is nervous and in a flap because he can’t quell the protests. He thinks if he shuffles the deck of security personnel, it will have an effect. Lukashenko is still betting on stifling the protests,” said political analyst Alexander Klaskovsky. Lukashenko also ordered the strengthening of armed volunteer militia units, which in theory already exist but in practice have not played a role in the crisis till now. “NOT YET OVER” The two other two new presidential aides are Valery Vakulchik, who spent eight years as head of the KGB security police, and former deputy interior minister Alexander Barsukov. Barsukov will be responsible for Minsk, Vakulchik for Brest on the Polish border, and Karayev for Grodno, near the borders with Poland and Lithuania.