Border police in western Romania found 26 migrants from Syria and Turkey trying to leave for the Schengen area in a truck containing hydrochloric acid canisters.
The truck was transporting the chemicals on the Turkey-Germany route, Xinhua news agency quoted the Arad Border Police as saying on Wednesday.
The foreign nationals were discovered hidden inside the semi-trailer during a police search.
Detailed checks were carried out after officers found the truck had a broken seal during a routine inspection at the border crossing point.
Preliminary investigations show that the truck was driven by a Turkish citizen, while 25 of the migrants were from Syria and one was from Turkey.
The Arad Border Police are investigating the driver for migrant trafficking, and the migrants for attempted fraudulent crossing of the state border.
Romania, which is close to the Schengen area and hopes to join the European border-free zone within the year, has become an important transit point for migrants in recent years.