Guinea-Bissau's deposed President Umaro Sissoco Embaló has arrived in neighbouring Senegal following his release by military forces that toppled his government this week, Senegal's authorities have announced.

It follows negotiations by the regional West African bloc Ecowas to secure his transfer amid rising tensions in Guinea-Bissau.

Senegal's foreign ministry said in a statement that Embaló had landed in the country "safe and sound" on a chartered military flight late on Thursday.

The military in Guinea-Bissau has already sworn in a new transitional leader, Gen Horta N'Tam, who will rule the coup-prone country for a year.

Wednesday's coup came a day before authorities were due to announce the provisional results of a presidential and parliamentary election.

The military has suspended the electoral process and blocked the release of the results.

It said it was acting to thwart a plot by unnamed politicians who had "the support of a well-known drug baron" to destabilise the country, and imposed a night-time curfew.