The Vatican spokesman confirms a deadly stampede broke out at a stadium a few hours before Pope Benedict XVI addressed young people in Angola.
The Rev. Federico Lombardi says the pope is "very upset" by reports that two people were killed in the crush.
The incident occurred as the stadium was opening its gates to people waiting outside, about four hours before the pope arrived.
Portuguese news agency LUSA cites an unidentified source at a local hospital as saying a man and a woman were killed, eight others were hospitalized with minor injuries, and 10 were given medical assistance at the site.
An AP reporter saw another stampede break out when the pope arrived, and at least 20 people were taken away in ambulances.