A Ukrainian MP, local officials, and National Guard members have been arrested over a major bribery scheme involving overpriced contracts for drones and electronic warfare systems, Ukrainian President Zelensky confirmed.

The arrests follow the restoration of independence to Ukraine’s top anti-corruption agencies, after public protests forced a reversal of a controversial bill seen as weakening their powers, according to Reuters.

Zelensky vowed “zero tolerance” for corruption—an issue central to Ukraine’s EU membership hopes.