DAKAR, Senegal (AP) — Gambian security forces blocked access to the electoral commission office Tuesday, refusing to let staffers enter, as several West African leaders arrived to urge the country's president to respect elections that voted him out of power after 22 years.

The head of the West African regional bloc, Marcel Alain de Souza, told French radio RFI that military intervention could be considered if President Yahya Jammeh does not step down. The bloc has warned that the tiny nation of 1.9 million could be plunged into violence if he doesn't respect a peaceful transition.

Jammeh initially acknowledged defeat, even conceding in a telephone call broadcast on state television, but last week he announced he was rejecting the Dec. 1 vote results. He alleges voting irregularities.

Liberia President Ellen Johnson Sirleaf, a Nobel Peace Prize leaureate, is heading the meetings with Jammeh. Other leaders from the regional economic bloc, known as ECOWAS include Nigeria President Muhammadu Buhari, Sierra Leone President Ernest Bai Koroma and Ghana President John Mahama, who also was just voted from office.

Soldiers remained in the streets Tuesday as Gambians worried about unrest, a stark contrast to days of celebration in the streets after Jammeh's loss. Jammeh, who seized power in a bloodless 1994 military coup, has long been accused of overseeing a government that imprisons, tortures and sometimes kill its opponents, according to human rights groups.

His ruling party has said it would file a petition to the Supreme Court challenging the election.

President-elect Adama Barrow has denounced Jammeh's rejection of the vote, saying he has no constitutional authority to call for a new vote or declare the election null and void. Jammeh's term expires in January.

The U.N. Security Council, the United States and other countries and international organizations have called for a peaceful transition of power and warned against the use of force.

An Associated Press reporter in Banjul, Gambia, contributed to this report.