SAO PAULO (AP) — One of the favorites for Brazil's presidential election next year has been hospitalized due to abdominal pains.

A statement issued Monday by the office of environmentalist Marina Silva said there was no diagnosis yet. But it said her condition had improved since she was hospitalized in the capital of Brasilia on Saturday.

Silva ran for president in 2010 and 2014, finishing third both times with about 20 percent of the vote.

Recent opinion polls place her in a strong position for the next election. She has been untainted by corruption scandals, which is a rare asset among Brazil's political elite since the eruption of the sprawling investigation into kickbacks and bribes at the state-run oil company Petrobras.