In total, 29 prisoners escaped on Friday from the detention facility after killing a guard, defence ministry news website 26sep.net quoted Amran police chief Abdullah Dabwan as saying.
Nine were still at large after the security forces killed one and captured the remaining 19, Dabwan said.
The police chief denied the escapees included Abdel Aziz Yahia al-Abdi, who was condemned to death in 2010 for the murder of a member of Yemen's small Jewish community, after a security official said he had done so.
The security source had also put the number of escapees at 10, and said three guards were killed.
Dabwan said that an investigation was being conducted into the circumstances of the escape.