Three US troops suffered non-combat injuries in the effort to make a temporary pier off the coast of Gaza into a conduit for humanitarian aid, with one in critical condition at an Israeli hospital, Reuters reports citing US officials.

The injuries were the first for US forces during the latest operation to bring humanitarian aid to Palestinians. US Vice Admiral Brad Cooper, the deputy commander of U SCentral Command (Centcom), told reporters that two of the troops had a sprained ankle and a minor back injury.

“Two were very minor, routine injuries. Those individuals returned to duty,” Cooper said. A third service member, injured on a ship at sea, was medically evacuated to a hospital in Israel, he said. A US defence official, speaking on the condition of anonymity, said the individual was in critical condition.

The Pentagon has said it will prioritise the safety of US military personnel. Social media images showed a US air defence system, known as the Counter Rockets, Artillery and Mortars (CRAM), firing into the sky while on the pier. US officials said troops were testing the system.

Daniel Dieckhaus of the US Agency for International Development said that since the pier opened last week, about 506 metric tons of aid had been handed off to humanitarian groups inside Gaza