The weapons, according to U.S. Central Command, were intended to resupply Yemen’s Houthi movement. Since November, the group has attacked dozens of merchant vessels off the Arabian peninsula, significantly disrupting commercial shipping in the region, and setting off an aggressive campaign by the United States and other countries to thwart the assaults and degrade the Houthis’ arsenal.

Officials have said Tehran, which arms the group and appears to be providing some help with targeting, is complicit in the violence.

When the accident occurred Jan. 11, Chambers, of Maryland, and Ingram, of Texas, were attempting to board a suspected smuggling boat off the coast of Somalia. One fell from a ladder, the other dove into the sea after him and both were quickly swept away by the waves, officials have said.

A search and rescue effort was halted Sunday after 10 days, and the men were declared dead.

Much remains unclear about how Chambers and Ingram were lost so quickly. The mission was undertaken with drones and helicopters already in the air to provide surveillance, and the sailors were wearing flotation devices, according to a defense official familiar with the operation. No one on the boat being boarded exhibited hostility, the official said, speaking on the condition of anonymity to describe the incident.

It is unclear whether the SEALs wore other gear that would have aided in a rescue operation, such as infrared lights or strobes, which U.S. troops often wear on missions so they can be easily identified by friendly forces. An investigation is ongoing, the Navy said.

Both were assigned to SEAL units based on the West Coast, part of Naval Special Warfare Group 1, the Navy said. Chambers enlisted in 2012. Ingram did so in 2019, according to short bios released by the service.

In a statement earlier Monday acknowledging the SEALs’ deaths, President Biden called them “the very best of our country, pledging their lives to protect their fellow Americans.”