THE HAGUE — Laurent Gbagbo, former Ivory Coast president, was prepared to go to any lengths — including using lethal force — to cling to power after losing elections in 2010, and should stand trial for his alleged involvement in postelection violence, the International Criminal Court’s prosecutor said Tuesday.

Fatou Bensouda said the world’s first permanent war crimes tribunal must mete out justice to Gbagbo for victims of the violence that plunged his country, once a beacon of democracy in West Africa, into bloody chaos.

‘‘We will show that Mr. Gbagbo and forces under his control are responsible for the death, rapes, serious injuries to, and arbitrary detention of, countless law abiding citizens’’ considered supporters of his rival Alassane Ouattara, Bensouda said.

She was speaking on the opening day of a hearing to judge whether prosecutors’ evidence is strong enough to merit putting on trial Gbagbo, 67, the first former head of state to appear before the 10-year-old court.

Bensouda said prosecutors will focus on four incidents to paint a picture of the violence that erupted after Ouattara was declared the election winner and Gbagbo refused to accept his defeat, declaring himself president and allegedly unleashing his forces and supporters to target his rival’s backers.