At least four people are dead after two floatplanes carrying cruise ship passengers collided in flight Monday afternoon near Ketchikan, Alaska, according to the US Coast Guard.
The passengers on both planes were guests on a Princess Cruises ship, the Royal Princess, which is on a seven-day trip.
The Coast Guard, which is leading an investigation into the crash, told CNN it is still looking for two people.
The crash happened around 1 p.m. (5 p.m. ET) and involved two floatplanes carrying Royal Princess passengers on separate excursions, Princess Cruises said. A floatplane is an aircraft with pontoons or floats that allow it to land on water.
One plane, operated by Taquan Air, was flying a shore excursion -- a tour of Alaska's Misty Fjords -- sold through Princess Cruises. It was carrying 10 passengers and a pilot, the cruise line said.
The second plane was carrying a pilot and four passengers on an independent tour, the company said.
One Taquan Air passenger died; the other nine were rescued and received medical attention, Princess Cruises said. The company didn't release the condition of the pilot.
Three people aboard the other plane -- two American passengers and an American pilot -- died, Princess Cruises said.
"Rescue efforts continue for the two other guests, one Australian and one Canadian," the cruise line said.
"We are deeply saddened to report this news and our thoughts and prayers are with those who lost their lives and the families of those impacted by today's accident. Princess Cruises is extending its full support to traveling companions of the guests involved," the company said Monday.
Taquan Air, a regional airline based in Ketchikan, released a statement saying it was "in the midst of an active crisis response, and our focus is on assisting these passengers, the pilot, our staff, their families and loved ones, and first responders."
"Taquan Air has suspended all scheduled flights and is cooperating fully with the National Transportation Safety Board (NTSB), the Federal Aviation Administration (FAA) and other authorities to examine every aspect of this event," the Taquan Air statement said.
The NTSB tweeted Monday night that it was launching a "go team" to investigate the collision.
The Royal Princess' current voyage originated in Vancouver, British Columbia, over the weekend and is scheduled to end Saturday in Anchorage, Alaska, the company said. Part of the voyage, the company's website said, included "scenic glacier viewing" with stops at Juneau, Ketchikan and Skagway.