The army launched a coup in the West Africa country of Guinea-Bissau (search) Sunday, arresting the president and ordering government ministers detained, news reports said.

An army spokesman announced the takeover on a radio station, the Portuguese news agency Lusa reported from Bissau, the capital. No shooting or injuries were reported, and a 7 a.m. to 7 p.m. curfew was imposed throughout the former Portuguese colony.

Portugal issued a statement urging the military to back down.

"The Portuguese government regrets the military coup today in Guinea-Bissau and appeals to those behind it to return constitutional legality to the country immediately," it said.

A communique said to be from the armed forces chiefs of staff was read over the radio Sunday morning, announcing the army was "taking constitutional power," according to Lusa.

It ordered all members of the government to report to a public building in the capital by 10:30 a.m., Lusa said.

The army said it would set up a Military Committee for the Restitution of Constitutional and Democratic Order, according to the report.

News reports said the streets of Bissau were calm. Phone lines into the country apparently were not working.

Guinea-Bissau, with a population of about 1 million people, is one of the world's poorest countries, according to the United Nations (search). Food shortages are common and basic public services often don't work.

President Kumba Yala (search) promised elections last February in an effort to stop political squabbling that has paralyzed the government. However, the ballot has been repeatedly postponed because of a lack of money and organizational difficulties.

Yala had promised a U.N. Security Council mission that passed through Bissau earlier this year that elections would be held Oct. 12, but the National Electoral Commisssion said last week it would not be ready in time

Other Portuguese-speaking nations have sent diplomats in an attempt to ease political tension in Guinea-Bissau. Recently, Nobel peace laureate Jose Ramos-Horta (search), the foreign minister of East Timor, visited Bissau to try to help.

Guinea-Bissau has still not recovered from an armed rebellion in 1998 that killed more than 2,000 people and ousted then-President Joao Bernardo Vieira.

Yala and his Social Renewal Party won 1999 presidential and legislative elections that were part of an accord to end the 11-month conflict.

Troops attempted to overthrow Yala in 2001 but were thwarted by loyalist soldiers.

Guinea-Bissau, which became independent in 1975, has been haunted by violence and poverty. Bissau, the capital, is without electricity, and many people lack basic amenities such as plumbing. Store shelves are largely bare and shops generally close in the mid-afternoon.

The city's main square is dominated by a bust of Cuban revolutionary Che Guevera, bullet holes from past conflicts still pockmark downtown buildings.