Four dead in shooting near Mexico's presidential residence

Four people have been killed and two more injured in a shooting near Mexico's National Palace.

Police said an armed man entered an apartment building near the Mexican President's official residence, seeking to relieve himself. 

When he was confronted by the residents he pulled out a pistol and opened fire, killing three people. 

The gunman was later shot dead by the police.

President Andres Manuel Lopez Obrador was travelling outside of Mexico City when the incident happened.