North American Aerospace Defense Command intercepted four Russian aircraft on Wednesday in the Alaska Air Defense Identification Zone, NORAD announced in a press release Thursday.

The U.S. military monitored two Russian Tu-95 bombers and two Su-35 fighters in the area. NORAD sent an E-3 Sentry, four F-16s, and four KC-135 tankers to identify and intercept them, according to the command.

Though the Russian move was seen as provocative, aircraft did not violate any sovereign airspace.