Russian bombers had entered North American defense zone a day earlier, US military officials said.

US fighter jets intercepted several Russian bombers in international airspace off the coast of Alaska on Tuesday, in the fourth and fifth such incursions this year, US military officials said on Wednesday.

"The Russian aircraft remained in international airspace and at no time entered US or Canadian sovereign airspace," the North American Aerospace Defense Command (NORAD) said in a statement posted on Twitter.

"This is the 4th and 5th intercepts this year and the 2nd day in a row that Russia has flown into the Alaskan ADIZ," NORAD said, referring to the Air Defense Identification Zone airspace surrounding the United States and Canada and defined for national security reasons.

Two pairs of F-22 fighter jets, each with an E-3 intercepted Tu-95 bombers Su-35 fighter jets entering the Alaskan ADIZ May 21. The bombers entered the ADIZ and were intercepted by two F-22s, exited and then re-entered the Alaskan ADIZ accompanied by two Su-35 fighter jets. pic.twitter.com/NYP6EVq2Xg — North American Aerospace Defense Command (@NORADCommand) 22 May 2019

Russian bombers had also entered the North American defense zone a day earlier, it added.

Earlier, on May 10, two US fighter jets intercepted two Russian bombers near Alaska, according to media reports.