A colleague of slain Honduran activist Berta Cáceres, known for her fight against the encroachment of hydroelectric dams and mines on indigenous lands, has been found dead.

Lesbia Yaneth Urquía's body was found dead by a road in the semi-rural town of Marcala, 100 miles west of the capital Tegucigalpa, security ministry spokesman Luis Osabas said.

He said the 49-year-old activist went missing on Tuesday after leaving her home on a bicycle.

Urquía is the third member of an indigenous rights organization called the Consejo de Organizaciones Populares e Indígenas de Honduras, or COPINH, to be murdered this year.

The group's award-winning leader Berta Cáceres was killed in March. Another member, Nelson García, was shot dead a few weeks later.

Honduran police have arrested five people for Cáceres' murder, including a representative of a hydroelectric dam whose construction faced local opposition.

Urquía fought against the construction of a hydroelectric dam in the La Paz region, COPINH said in a statement.

The group added that the dam is owned by the husband of Congressional Vice President Gladys López and said it held them and the government responsible for Urquía's murder.

López and her husband could not be reached for comment.

Police inspector Eddie López told reporters gathered in Marcala to cover the murder, that Urquía owned two hotels and a small market and had reported being a victim of extortion. He said her death is being investigated as a family property dispute and as an extortion case.

Honduras has one of the highest murder rates in the world.