On Saturday night, the Alianza F.C. and Club Deportivo FAS teams were playing a quarter-final game at the Cuscatlan stadium in San Salvador, the capital.
Play was suspended after a stampede broke out in the general section of the stadium, a venue with a capacity for more than 44,000 fans.
"The Salvadoran Football Federation deeply regrets the events that occurred at the Cuscatlan Stadium," the organization wrote on Twitter. "It also expresses solidarity with the relatives of those affected and deceased in this incident."
The tweet added the organization would immediately request a report on the incident.
(Reporting by Maria Ponnezhath in Bengaluru; Nelson Renteria in San Salvador, writing by Sarah Kinosian; Editing by Christian Schmollinger)
