The two nuclear-capable Tu-95 bombers were spotted by U.S. military radar at 5 p.m. local time, Fox News reported on Wednesday.
Unlike a similar incident Monday night, this time the U.S. Air Force did not scramble any fighter jets.
Instead, it launched a single E-3 Sentry early warning aircraft, known as AWACS, to make sure there were only the two Russian bombers flying near Alaska, and not other aircraft flying underneath the large bombers.
U.S. territorial waters extend 12 nautical miles from shore.
Two Russian bombers flew within 100 miles of Alaska on Monday night.
Read alsoRussian bombers fly near Alaska, U.S. Air Force scrambles jets – mediaThe Russian bombers took off from an airbase in Petropavlovsk, Russia and returned five hours later to an airbase in Anadyr. Both locations are in eastern Russia, some 1,000 miles away.
Last week in Moscow, Secretary of State Rex Tillerson said U.S.-Russian relations were at a "low point" during a news conference with Russian Foreign Minister Sergey Lavrov.
While Tillerson was in Moscow, a trio of Russian bombers flew near the east coast of Japan, forcing the Japanese military to scramble 14 fighter jets at various times to intercept the bombers. A Russian spy plane traversed Japan's west coast.
Before Monday's flight near Alaska, the last time Russian bombers flew near the U.S. was July 4, 2015, when a pair of Russian bombers flew off the coasts of Alaska and California, coming as close as 40 miles to Mendocino, Calif.
Russian President Vladimir Putin called then-President Barack Obama to wish him a happy Independence Day while the bombers cruised the California coastline.
In February, a Russian spy ship sailed up and down the East Coast of the U.S. while remaining in international waters.