LAGOS, Nigeria (AP) — Hundreds of Nigerians are protesting against poverty and corruption as President Muhammadu Buhari's prolonged absence for medical tests abroad raises political and economic tensions.

Protester Omoyele Sowore says Nigerians are tired of his "absentee government." Prices of food and other goods have soared as Nigeria confronts low international prices for oil on which the government depends and a devalued naira currency because of massive shortages of foreign currency.

Despite Buhari's campaign promise to fight endemic corruption, his government has not achieved any successful high-profile prosecutions.

A spokesman says Buhari is extending his two-week vacation in London to complete unspecified medical tests. Songhai Advisory risk analysis says the indefinite extension fuels suspicions about the 74-year-old leader's capacity to govern and increases political and economic uncertainty.