BUJUMBURA, Burundi — In a circular ward of the Prince Regent Charles Hospital, a facility that speaks of better days in this central African country, Armel Manirambona lay on a bed under a white blanket that covered a bullet wound in his abdomen and damage to his colon and liver.

“We were running in the street, and then I was shot,” said Mr. Manirambona, 27, an information technology worker with a university degree who lives in the Buterere neighborhood in Bujumbura, the capital. “I don’t remember anything.”

Mr. Manirambona is one of scores of people who have been wounded in recent days while demonstrating against President Pierre Nkurunziza, whose pursuit of a third term in office has thrown the country into crisis. The protests have been met harshly by security forces, and at least 20 people have been killed, including two on Thursday, the Red Cross reported.

Mr. Nkurunziza’s bid, announced on April 25, is raising questions because the Constitution says a president’s five-year mandate may be renewed only once. His contention, rejected by opponents, is that his first term should not count toward the limit because he was initially elected in 2005 by Parliament, not voters.