"We had no intention of killing the hostages until the Americans began shooting at us," Liban Muse told the Los Angeles Times.
"Our preference is only to take ships and ransom money, not to kill. But governments are targeting and killing our people."
Jean Adam, 66, and 70-year-old Scott Adam, the yacht's Californian owners, and two others, Phyllis Macay, 59, and Bob Riggle, 67, from Seattle, were on board the S/V Quest, reportedly heading for the coast of Somalia, when it was seized Friday afternoon 240 nautical miles off the coast of Oman.
US Central Command (CENTCOM) announced Tuesday that the four were killed by their captors.
US forces aboard four navy warships had been monitoring the captured vessel for approximately three days and had been taking part in negotiations to secure the release of the four Americans.
Two pirates boarded the USS Sterett to participate in negotiations. It was unclear if any ransom was offered to the pirates.
As the talks continued Tuesday, the pirates aboard the yacht fired a rocket-propelled grenade toward the USS Sterett "with absolutely no warning," Vice Adm. Mark Fox, commander of US Naval Forces Central Command, said in a telephone briefing.
Gunfire then erupted inside the yacht's cabin, after which pirates appeared on the deck of the yacht and moved toward the bow with their hands in the air to surrender.
US Special Operations Forces boarded the yacht by small boat and discovered the four American hostages had been shot.
"Despite immediate steps to provide life-saving care, all four hostages ultimately died of their wounds," CENTCOM said in a statement.
The US forces killed one pirate with a firearm and another with a knife as they cleared the yacht. The remains of two other pirates were discovered aboard the Quest.