MOSCOW — The police in Belarus used tear gas to disperse protesters on Sunday after President Aleksandr Lukashenko, presiding over a ceremony to commemorate Belarus’s Independence Day, said in a speech that shadowy forces based in “the capitals of other countries” were plotting to bring down his government.

“We must strongly and consistently oppose the unconscionable scenario of the ‘colored revolutions,’ which are written as a blueprint in the capitals of other countries,” Mr. Lukashenko said, alluding to the uprisings that led to pro-Western governments in Ukraine and Georgia.

The goal, he said at the open-air ceremony in Minsk, the Belarus capital, is to force nations into a “new world order,” which would strip them of their assets and self-determination.

“We understand that the goal of these attacks is to impose uncertainty and anxiety and to destroy public harmony,” said Mr. Lukashenko, according to an official transcript. In the end, he said, the aim is “to put us on our knees and to bring all the achievements of our independence down to zero. This is not going to happen!”