The incident occurred this Tuesday in Rosario's International Airport "Islas Malvinas". Hours before Messi had planned to take his flight back to Spain, an individual activated the anti-terrorist protocols after declaring he had a bomb in his luggage.
According to 'TyC Sports', the event occured when said individual was about to check in his luggage. His behaviour aroused suspicion among aiport authorities, and he ended up confessing to have brought a bomb in his suitcase. That statement made the Airport Security Police activate the necessary protocols. The airport was shut down and the people inside evacuated.
The situation was resolved in an hour, after which point Rosario's airport returned to normality. Therefore, Messi's return flight back to Spain shouldn't be inconvenienced further, although it will go ahead without a planned hour of take-off.