Protests have taken place in the US state of Louisiana after a video emerged appearing to show two white police officers holding down and shooting dead a black man.

The incident took place in the state capital, Baton Rouge, on Tuesday after reports of a man threatening people with a gun outside a shop.

A post-mortem examination showed the victim, Alton Sterling, 37, died of gunshot wounds to the chest and back.

Protests later blocked nearby roads.

The crowd of about 200 people was moved on by police but organisers say they will reassemble in front of City Hall.

The incident comes amid heightened tension in the US over the deaths of African-American men at the hands of police.

There are more than 1,000 deadly shootings by police in the US each year, and those killed are disproportionately black Americans.

(BBC)