Ghana's national security adviser says the authorities were questioning a group of people suspected of plotting against the government.
"They've been meeting and we're aware of it...If it's a coup they're plotting, then we're saying that they had better have a re-think because it will fail and the people of Ghana will not stand for it," General Joshua Hamidu told Reuters.

He said the alleged plotters were believed to have been planning to cause trouble between May 15 and June 4.

The two dates are celebrated in the West African country by supporters of former President and two-time coup leader Jerry John Rawlings, who led an army mutiny on May 15, 1979 and went on to seize power on June 4 of the same year. He did not say how many people were being questioned and did not identify those being questioned.

Political tension rose in Ghana after the government of President John Kufuor accused the opposition of whipping up public anger over a soccer stampede in which 126 people were killed last Wednesday. The tragedy triggered anti-police riots during which some protesters chanted for the return of Rawlings, who stepped down in January after nearly two decades in office, setting a rare example of a peaceful, democratic transfer of power in Africa.

Police briefly detained a former Minister and senior official in Rawlings's National Democratic Congress party on suspicion of having orchestrated the protests. Several other senior officials from the old administration are due to stand trial this week on corruption charges. Since independence from Britain in 1957, Ghana has experienced five successful military coups and many attempted ones.