A stampede at a church gathering in Liberia's capital Monrovia killed 29 people overnight, the deputy information minister told state radio on Thursday (local time).
The incident occurred during an all-night Christian worship event at New Kru Town, a neighbourhood on the outskirts of the capital, Jalawah Tonpo said.
"The doctors said 29 persons died and some are on the critical list," Tonpo said, calling into state radio from a nearby hospital.
"This is a sad day for the country."
Speaking to The Washington Post, police spokesman Moses Carter confirmed 11 children and a pregnant woman are among the 29 victims.
The toll is expected to grow, he said, and an investigation is underway.
Exodus Morias, a resident who attended the event, told Reuters the stampede began after a group of armed men rushed the crowd in an attempt to stage a robbery.
"We saw a group of men with cutlasses and other weapons coming toward the crowd," Morias said.
"While running, some people dropped and others fell on the ground and walked over them."
Carter told The Washington Post that worshippers had gathered on a fenced-in soccer field outside a school in New Kru Town when the men attacked shortly after nightfall, attempting to "hijack their personal effects".
As attendees rushed toward the exit, panic enveloped the crowd, resulting in the stampede, he said.
Bands of Liberian street gangs, known as Zogos, commonly commit robberies with machetes and other small weapons.
President George Weah, who is expected to visit the site on Thursday afternoon, declared a three-day period of national mourning and said the Liberian Red Cross and Disaster Management Agency had been called in to assist victims, his office said.