The anti-fossil fuel Code Red coalition said hundreds of demonstrators were detained by police during the action aimed at disrupting the aviation industry.
"In Liege, activists are blocking Chinese e-commerce giant Alibaba. Planes filled with consumer goods from China cannot be unloaded and trucks cannot leave the site," Code Red said in a statement.
"In Antwerp, with 40 activists still on location, the air traffic of private jets is paralysed despite over 700 other activists being arrested."
An AFP journalist at the airport near the city of Antwerp said that police had fired tear gas and forcefully detained protesters dressed in white overalls as they tried to storm into the facility.
The protest is the latest in a string of civil disobedience actions by the Europe-wide Code Red coalition in Belgium.
Chinese giant Alibaba opened its 30,000-square-metre European distribution hub in Liege in 2021.
"Liege airport is the fastest growing airport in Europe," said Code Red activist Louis Droussin in a statement.
"Millions of euros of public money support this expansion, which is to the detriment of hundreds of hectares of agricultural land."
