Washington (dpa) - The United States offered condolences to the families of three Turkish police officers who were killed on Wednesday when gunmen attacked the US consulate in Istanbul. 

The three officers were guarding the main gate into the consulate when suspected terrorists leapt from a vehicle and opened fire. All three gunmen died in the firefight, which lasted several minutes. 

"We express our deepest condolences to the families of the three Turkish police officers killed, as well as their colleagues who were wounded in the attack," US State Department spokesman Sean McCormack said. 

"The Turkish National Police really were the first line of defense here. And they acted with extraordinary courage in repelling this attack." 

One of the police officers died at the scene, and the two others passed away in a hospital, Turkish authorities said. 

Turkish police said that the gunmen had ties to the terrorist network al-Qaeda, but McCormack he could not confirm that allegation. (dpa)