Spanish navy boats protecting an oil drilling ship rammed Greenpeace boats during a protest, leaving one activist with a broken leg and another with minor cuts.

Dramatic footage filmed off the Canary Islands of Lanzarote and Fuerteventura on Saturday shows the moment when a navy rhib – a fast rigid hull inflatable boat – appeared to deliberately collide with a Greenpeace rhib which was approaching the oil ship Rowan Renaissance.

Matilda Brunetti, a 23 year-old Italian, can be heard screaming in pain in the video as her leg was broken and she was thrown into the water. According to a colleague, she then received cuts to her legs from a propeller, before she was taken by the Spanish navy to a hospital in Las Palmas, Gran Canaria, where she is now recovering.

“I was scared. Not scared for me. Scared for Matilda. I couldn’t see her, I could only hear her screaming,” said Pablo Accattoli, 32, who was also on one of the rhibs and has been on Greenpeace ships since 2012.

“This kind of chasing and violence, I haven’t seen anything like that before. It was way out of proportion, they didn’t look like they were in control.”

The protest against oil drilling in the Canary Islands follows Spanish government’s approval for oil exploration in August, which has faced opposition from the islands’ authorities, environmentalists and local people.

Repsol, the Spanish energy company, said the Rowan Renaissance was intended to start drilling on Tuesday but the exact start date would depend on weather conditions.

A spokesman said Repsol had no comment to make on the Greenpeace protest but said: “Our assumption is that we could be finding a reservoir with 100,000 barrels of oil a day, which would reduce Spain’s energy dependency from 99.9% to about 90%, saving the country about €4bn [£3bn] a year [in imports]. Spain consumes just over 1m barrels of oil a day. Our firm belief is this in the best interests of Spain.”

The Spanish ministry of defence, which tweeted its own photographs of the incident, said in a statement that Greenpeace had ignored repeated requests to stay out of an exclusion zone, which extends for one maritime mile from the oil drilling site. It said that navy crew on rhibs deployed from the patrol vessel Relámpag, which is escorting the Rowan Renaissance, were in place to prevent harassment of the oil drilling ship and stop activists boarding it.

Estado Mayor Defensa (@EMADmde) Momento del rescate de la activista de @Greenpeace por militares del patrullero Relámpago P43 de la @Armada_esp pic.twitter.com/Wt1pW4C66A

The Greenpeace vessel that launched the rhibs, the Arctic Sunrise, remains in the vicinity but outside the exclusion zone. It is the first time the ship has been in a oil protest since it left Russia in August, after being impounded in Minsk for nearly a year following a protest against Gazprom’s oil drilling in the Arctic.

On a separate Greenpeace film from Saturday, the Relámpag can be heard radioing the Arctic Sunrise’s captain: “If you don’t want to withstand further actions, you are to leave this restriction zone as soon as possible. I kindly request you to leave this area as soon as possible.”

The Greenpeace captain, Joel Stewart, replies: “We are going to remain in position. We are obligated to stay here as our duty is to protect the environment. We will not allow reckless oil drilling by the Rowan Renaissance in these deep waters as it is considered by us and our millions of supporters to be extremely reckless and we are calling on the Spanish government to protect the environment and to protect the people of the Canary Islands and not to be protecting the corporate profits of Repsol.”