A panicked crowd at a political rally in southern Nigeria trampled at least 11 people to death and injured dozens more as President Goodluck Jonathan gave a speech promising to change Africa's most populous nation for the better, authorities said Sunday. The stampede at the rally in Port Harcourt was to serve as a homecoming for a leader born in the oil-rich region. Instead, the rally highlighted the country's volatility ahead of April's national elections, and Jonathan's convoy caused a fatal traffic crash even before the stadium melee. Organizers held the rally Saturday at Port Harcourt Liberation Stadium, a soccer venue that can hold about 25,000 people. As Jonathan began his speech, some attendees began to try to leave to beat the traffic out of the stadium, while others pushed their way inside to hear his speech, said Ibim Semenitari, a Rivers state government spokeswoman. Eleven people died in the crush, Rivers state police spokeswoman Rita Inoma-Abbey said. Semenitari said at least 46 others had sought treatment at hospitals.