TEGUCIGALPA (Reuters) - Hooded gunmen shot dead two land rights activists in Honduras, the government confirmed on Wednesday, the latest in a string of attacks on rights groups in the Central American country.

Jose Angel Flores, 64, was president of the Aguan Unified Farmers Movement (MUCA), a group that opposes agriculture companies that grow African oil palm in a conflict over ownership and use of land. The other activist killed, Silmer George, was part of the same group.

The two men died Tuesday evening after hooded men with rifles shot at them as they left a meeting in the city of Tocoa, 240 kilometers (149 miles) north of the capital, Tegucigalpa. Flores and George had received threats before.

"Honduras has turned into a 'no-go zone' for anyone daring to campaign for the protection of the environment," Erika Guevara-Rosas, Americas director at Amnesty International, said in a statement.

"How many more activists have to be brutally murdered before the authorities take effective action to protect them, or even be willing to talk about this crisis?"

Government Security Ministry spokesman Luis Osabas said the killings were being investigated and that, as yet, there was no hypothesis of the motives or suspects.

Honduras is the third-largest producer of African oil palm in Latin America, exporting some $300 million worth in 2015.

MUCA estimates that more than 150 farmers and some 20 security agents working for agriculture firms have died since 2009 in clashes over land rights in Honduras.

The most emblematic case was Berta Caceres, the award-winning Honduran environmental rights activist who was shot and killed at her home in March.

(Reporting by Gustavo Palencia; Writing by Enrique Andres Pretel and Christine Murray)