(JTA) — Iran freed the 10 U.S. Navy sailors it detained after their two boats accidentally floated into Iranian territorial waters.

The sailors, nine men and one woman, were released Wednesday, a day after being detained by the Iranian Revolutionary Guard and held at an Iranian base on Farsi Island. They left on their boats.

“After determining that their entry into Iran’s territorial waters was not intentional and their apology, the detained American sailors were released in international waters,” a statement posted online by the Revolutionary Guard said Wednesday.

U.S. officials, including Vice President Joe Biden and State Department spokesman John Kirby, denied there was any U.S. apology.

“There’s nothing to apologize for,” Biden said on “CBS This Morning.” “When you have a problem with the boat, you apologize the boat had a problem? No, and there was no looking for any apology. This was just standard nautical practice.”

Photos released by Iran show the sailors at the time of their capture kneeling on the deck of their boat with their hands behind their heads, as well as sitting on the floor while in detention. The female soldier’s head is covered by a brown cloth.

The sailors were traveling from Kuwait to Bahrain, according to the U.S. Defense Department.

Defense Secretary Ash Carter in a statement thanked Secretary of State John Kerry “for his diplomatic engagement with Iran to secure our sailors’ swift return.”

“Around the world, the U.S. Navy routinely provides assistance to foreign sailors in distress, and we appreciate the timely way in which this situation was resolved,” Carter said.

The 5th Fleet spokesman, Cmdr. Kevin Stephens, told The Associated Press that the soldiers would be debriefed and reintegrated with their unit. The priority now is “determining … how exactly these sailors found themselves in Iran. And that’s something we’re going to be looking at,” he said.

Both the United States and Iran blamed the potential international crisis on “mechanical trouble.”

Separately, Iran said Wednesday that it expects the final implementation of its nuclear deal with the world powers to go into effect early next week, after the International Atomic Energy Agency reports as early as Friday on its current inspection to determine that Iran has fulfilled its obligations under the agreement, according to reports.