Four masked men attacked and robbed an out-of-state broker of up to $1 million in diamonds late Thursday morning near the Galleria in Far North Dallas, police said. Shortly before noon, the man was getting into his car in a parking garage along the Dallas North Tollway near Galleria Road when four Hispanic men drove up in a red sport utility vehicle and blocked him in, police said. The men, who were dressed in black, got out and opened all of the broker’s doors while speaking Spanish. They pulled him out at gunpoint, a struggle ensued, and the man was stabbed twice in the leg, police said. The group also took his clothes, according to a police report. The man, whose name was not released, was hospitalized in fair condition. The victim lives in New York. The attackers fled with between $500,000 and $1 million worth of diamonds, police said. The well-organized heist is the latest in a string of attacks on diamond brokers in the Dallas area and in more than a dozen major cities nationwide, police said. The assailants typically are from out of the country, conduct surveillance on potential victims and flee the area quickly after their crimes, police said. “It’s like a military operation,” said Dallas police robbery Sgt. Ross Salverino. “They all do it the same way, and it’s difficult to identify them at this point.” Salverino said the assailants often quickly abandon the vehicles used in the heists or change the license plates. Investigators do not believe there is surveillance video of Thursday’s attack, he said. Houston, Chicago, Denver and Miami are among other major cities that have seen such robberies in recent years, Salverino said. “It’s not necessarily the same people, but it’s got to be the same organization because they do it almost the same way,” he said.