MEXICO CITY — Four men have been arrested in the murder of a Honduran environmental and indigenous rights activist whose killing two months ago prompted international condemnation, the authorities said on Monday.

The activist, Berta Cáceres, led a decade-long fight to block construction of the Agua Zarca Dam along the Gualcarque River, which is sacred to her Lenca people. Despite numerous threats and the killings of other members of her organization, she was undeterred.

She was awarded the prestigious Goldman Environmental Prize last year, but the international acclaim was not enough to protect her. On March 3, gunmen burst into the house where she was staying in La Esperanza, her hometown, in western Honduras, and fatally shot her.

The suspects were arrested in raids early Monday. Two of them are linked to the Honduran company that is building the dam, Desarrollos Energéticos S.A., or DESA.