ISTANBUL, Turkey —  Al Qaeda militants attacked the U.S. consulate in Istanbul on Wednesday, killing six people, according to a police official who spoke on condition of anonymity because he was not authorized to brief journalists.

Wielding pistols and shotguns, the attackers struck a police guard post outside the consulate, sparking a gunbattle that left three attackers and three officers dead.

“It is an obvious act of terrorism,” U.S. Ambassador Ross Wilson said in a statement.

The U.S. ambassador to Turkey and Turkey’s foreign ministry said security around all American diplomatic missions in Turkey had been increased.

Yavuz Erkut Yuksel, a bystander, told a television station the attackers emerged from a vehicle and surprised the guard.

“One of them approached a policeman while hiding his gun and shot him in the head,” Yuksel said.

Footage from a security camera at the site showed four armed and bearded men emerging from a car and killing a traffic policeman, then running toward a guard post some 50 yards away as other policemen fired back, the Dogan news agency reported.

[1] http://www.foxnews.com/story/0,2933,378346,00.html