Media playback is unsupported on your device Media caption The USS Fitzgerald damaged by its crash

The former commanders of two US Navy destroyers involved in collisions last year are to face charges including negligent homicide, the navy says.

The USS Fitzgerald and a Philippine container ship collided in June, leaving seven navy sailors dead.

Two months later, the USS John S McCain and an oil tanker collided near Singapore, killing 10 navy sailors.

Investigations have already found that both incidents were preventable and the result of "multiple failures".

In the aftermath of the collisions, Vice Adm Joseph P Aucoin was dismissed as commander of the Seventh Fleet.

The navy said in a statement that the then commanding officer of the USS Fitzgerald and three other lower-ranking officers will face charges including dereliction of duty, hazarding a vessel and negligent homicide.

The then commander of the USS John S McCain faces charges of dereliction of duty, hazarding a vessel and negligent homicide, the statement added.

The navy said the charges would be presented to what it calls an Article 32 hearing which will determine if there is enough evidence to warrant a general court martial.

"The announcement of an Article 32 hearing and referral to a court martial is not intended to and does not reflect a determination of guilt or innocence related to any offences," it added.

"Additional administrative actions are being conducted for members of both crews including non-judicial punishment for four Fitzgerald and four John S McCain crew members."

Media playback is unsupported on your device Media caption The USS John S McCain suffered damage midships to port

The USS Fitzgerald was in collision with the Filipino-flagged ACX Crystal in the early hours of 17 June in Tokyo Bay, causing a large gash below the destroyer's water line that flooded lower decks.

The US 7th Fleet said in a statement that the collision was avoidable and that both ships demonstrated "poor seamanship".

Bodies of the victims were found in their bunks by divers. There were no casualties on the Filipino ship

The commanding officer at the time, Cmdr Bryce Benson, was trapped in his cabin and crew members had to use a sledgehammer to free him. He was later fired from his position.

The USS John S McCain and an oil tanker, the Alnic MC, collided east of Singapore on 21 August. The collision left a large hole in the destroyer's side and flooded compartments including crew berths.

Commanding officer Cmdr Alfredo J Sanchez was later sacked due to a "loss of confidence".

The Alnic MC sustained damage but none of its crew were injured.

The collision was the fourth such incident involving US warships in a year and sparked calls for a thorough investigation into leadership failures and naval procedures in busy shipping lanes.

In a subsequent report on the collisions, Chief of Naval Operations Adm John Richardson said: "Both of these accidents were preventable and the respective investigations found multiple failures by watch standers that contributed to the incidents."