Alaska Airlines is pausing flights to Hawaii, where an emergency proclamation is issued ahead of tsunami waves expected to hit the islands Tuesday evening.

“As a safety precaution, flights en route to Hawaii are returning to the mainland or diverting as needed,” a spokesperson for the airline said in an email.

While flights haven’t been outright canceled, the airline warns that cancelations may happen. Those with flights to and from Oahu (HNL), Kona (KOA), Kauai (LIH), and Maui (OGG) on Tuesday or Wednesday are eligible to switch or cancel their flights.

“We are monitoring airport conditions with government agencies and could see operational impacts. A waiver is in place allowing guests to adjust their travel plans,” the spokesperson said.

Hawaii Gov. Josh Green has issued an emergency proclamation Tuesday evening after a warning was issued for the islands following an 8.7 magnitude earthquake near Russia.

The waves threaten to cause damages to “the health, welfare, and living conditions of a substantial number of persons, and to affect the economy and natural resources” of Hawaii, Green wrote.

Cars jammed streets and highways in Honolulu as the tsunami alerts coincided with the Tuesday afternoon rush-hour, according to The Associated Press. Warning sirens blared as people moved to higher ground. Hawaii schools canceled after-school and evening activities.

The Pacific Tsunami Warning Center in Honolulu said the tsunami generated by the quake could cause damage along the coastlines of all the Hawaiian islands.

“Urgent action should be taken to protect lives and property,” the warning stated. The first waves were expected around 7 p.m. Tuesday local time (10 p.m. PDT).

Material from the Associated Press is included in this report.