Dhaka, Dec. 25 -- The European Union has warned it may take action against what it called "unjustified measures" after the United States barred five European nationals accused of pressuring US technology companies to censor American viewpoints.

The warning came Wednesday from the European Commission after US Secretary of State Marco Rubio announced travel restrictions against the five, whom he described as "radical" activists linked to "weaponized" nongovernmental organisations. Among them is former EU commissioner Thierry Breton, who previously oversaw Europe's digital and social media regulations.

Breton, a former French finance minister, clashed publicly last year with tech billionaire Elon Musk over content moderation and an online ...