BISSAU (AFP) - The troops who seized power this month in the tiny West African nation of Guinea-Bissau said Friday they have agreed to a 12-month transition period mooted by the west African regional bloc ECOWAS.

The junta, which initially proposed a two-year transition, has also agreed to free detained leaders, their spokesman Daba Na Walna said.

A team of the country's former rulers is due to arrive later Friday in Abidjan, the Ivory Coast's main city, the Ivorian presidency said.

Ivory Coast President Alassane Ouattara, current head of the Economic Community of West African States or ECOWAS, has pledged a firm response to the instability "to prevent our sub-region from giving into terrorism and transnational criminality".

The regional bloc on Thursday decided to send troops to Guinea-Bissau, an impoverished former Portuguese colony and Mali, where disgruntled soldiers also staged a coup.

The Bissau junta is holding, among others, president Raimundo Pereira and prime minister Carlos Gomes Jr. The coup aborted the first round of a presidential election.