A security guard working at the central prison was killed, along with his daughter and two others, in an ambush planned by terrorists in the city of Ta'izz city, the Yemeni Ministry of Interior said on Tuesday.

A ministry statement said the armed men were veiled when they fired at the guard, Saleh Al-Aolaqi, who was with Raghad; his six-year-old daughter, and two of his companions.

Four others were injured in the incident and rushed to the nearest hospital, the statement added.

Investigation is underway on the incident, noted the statement.