Tensions high after another shooting

Tensions are high in Missouri this Christmas after the shooting of a black 18-year-old miles from where Michael Brown was killed this summer.

Protesters blocked traffic on an Interstate highway and gathered at the gas station in Berkeley, Mo., where Antonio Martin was shot on Tuesday.

{mosads}While the number of demonstrators was down from the previous night, the protests highlight continued nationwide tensions between police and minority communities.

Berkeley Mayor Theodore Hoskins has said a video shows Martin pulling a gun on the officer who shot him. Martin was being questioned about a theft at a convenience store.

Hoskins, who is African-American, also said the situation is different from Ferguson, a St. Louis suburb just miles from Berkeley, because the police force in Berkeley is overwhelmingly black.

In Ferguson, where Brown’s killing by a white police officer set off days of rioting over the summer, an overwhelmingly white police force serves a black community.

The shooting of Martin comes just days after two New York City police officers were gunned down in an ambush-style attack in Brooklyn. The man suspected of the killings, who later shot and killed himself, had posted messages on social media suggesting he wanted revenge for the killings of Brown and Eric Garner, a Staten Island man killed after being placed in a chokehold by a police officer.

Grand juries did not deliver indictments in the deaths of Brown or Garner.

Police across the country have been on alert since the killings of the two New York policemen.

President Obama has formed a commission that is looking for ways to improve the relationships and communication between police and minority communities.

Martin is the third young black man killed by a white police officer in the St. Louis area since Brown was shot and killed.