Anis Hamza, medical director of Clinique les Oliviers in Sousse, said two ambulances were sent to the scene and more injured people were brought in by car.
His clinic dealt with 15 patients, he said, one Russian, a Ukrainian and the rest were British.
He told Sky News: “We received many kinds of injured and we did our best.
“The Tunisian people were here to help.
“All the staff stayed here, nobody went to their house.”
He said two British patients were still receiving treatment in intensive care.
“They are out of danger, they are safe,” he said. The others have been discharged.
Locals were shocked by the attack, the medical director said. “Tunisians are kind, we hate violence, we don’t like this kind of people.”
Ross Thompson and Rebecca Smith, from Coventry, are recovering after suffering shrapnel injuries.
His mother Mandy wrote on Facebook that his foot and arm were in a cast while his girlfriend’s injuries were all over her body, but that they were safe and hoping to fly home soon.
She posted later: “What fantastic people we have in our lives.
“The support from family, friends and even strangers has been overwhelming.
“Thank you each and everyone of you, you have all helped us as a family today to stay strong.”
Mr Thompson told Sky News they fled and hid indoors.
“We managed to get the room barricaded, got down low and just hid,” he said.
His girlfriend, with a dressing on her injured chin, said she got separated from her partner and hid in the staff toilets with another woman and her son.
“We locked ourselves in and hoped for the best.”
Dave Beardsmore, from Manchester, described bullets whizzing over his head as he fled after a local worker shouted to people to get off the beach.
“I saw mayhem, people were all over the place, people were running,” he told Sky News.
“I was saying ‘Move, move, move, run! Don’t look back!’
“We ran for our lives.
“I heard bullets going over the top of my head, I just kept on running and we went to our room.”
He and his wife were desperate to get a flight home after their ordeal, he said