Senegalese Prime Minister Ousmane Sonko on Friday said this week's coup in neighbouring Guinea-Bissau was a sham and demanded its disrupted election to be allowed to continue, adding to a chorus of regional anger over the latest power grab.

The coup reflects a continued a pattern of instability in Guinea-Bissau, a notorious cocaine transport hub with a long history of military interventions in politics.

Guinea-Bissau military officers installed Major-General Horta Inta-a as transitional president on Thursday, a day after soldiers toppled the civilian leadership before the results of weekend presidential and legislative elections could be announced.

The presidential contest pitted incumbent President Umaro Sissoco Embalo against Fernando Dias, a 47-year-old relative political newcomer who claimed he was on track to win.

"What happened in Guinea-Bissau was a sham. We want the electoral process to continue," said Senegal's Sonko, responding to questions from lawmakers. "The (electoral) commission must be able to declare the winner."

GENERAL SAYS COUP TO STAVE OFF 'NARCOTRAFFICKERS'

In his first public appearance as leader on Thursday, Inta-a said the coup was necessary to stave off a plot by "narcotraffickers" to "capture Guinean democracy" and vowed to oversee a transition that would last one year, beginning immediately.

Embalo arrived in Senegal on Thursday aboard a special flight following an intervention by the West African regional bloc ECOWAS, Senegal's foreign ministry said in a statement.

ECOWAS condemned the coup in a statement on Thursday and announced it was suspending Guinea-Bissau. The bloc called for the armed forces to return to their barracks and said it would send a high-level mediation mission.

Nigeria, home to ECOWAS headquarters, issued a separate statement condemning the coup and urging the safety of election observers to be ensured.

Nigerian former President Goodluck Jonathan, who had been observing the vote as part of the West African Elders Forum, was not reachable for much of Thursday and his whereabouts unknown, though a foreign ministry spokesperson said later he had managed to get on a special flight out of the country and was safe.

The European Union and African Union chairperson Mahmoud Ali Youssouf have also called for a return to constitutional order.