Buhari dismisses criticism following suspension of country's top judge

President of Nigeria Muhammadu Buhari has been faced criticism from opposition leaders and on social media.

Lagos, Nigeria (CNN)Nigerian President Muhammadu Buhari has come under intense scrutiny for suspending his country's Chief Justice just weeks before a general election, a move that critics have attacked as tyrannical and unconstitutional.

Buhari defended his decision on Twitter, saying corruption allegations against Chief Justice Walter Onnoghen -- who has been accused of failing to disclose bank accounts in foreign currencies -- are "grievous."
But the move was labelled a "coup against democracy" by the President of the Nigerian Senate, and prompted an outcry from the country's major opposition party, which halted its presidential election campaign temporarily in protest.
Describing the action as a "dangerous and brazen assault on the constitution," the Campaign Council of the opposition People's Democratic Party (PDP) said Friday that there was no point in campaigning in an election whose basis has been so flagrantly undermined.
"When democracy comes under this kind of virulent attack, then the election itself becomes superfluous," the statement said.
Buhari is seeking a second term as president in next month's elections, but his party has been accused of vote-buying by political opponents.
As the country's top judge, Onnoghen would have ruled on any legal challenge to the election.
That potential responsibility would now fall to Ibrahim Tanko Muhammad, whom Buhari swore in as acting Chief Justice of Nigeria (CJN) following his suspension of Onnoghen.
But many Nigerians have used social media to criticize Onnoghen's ousting, calling Buhari a tyrant and saying it's the President who should go.
They have been joined by numerous politicians from opposition parties, who have launched a cascade of condemnation against Buhari and urged him to reverse the decision.
"President Buhari has sent a dangerous signal to the entire world that Nigeria is no longer a democratic nation and that we have returned to the old, jaded era of military dictatorship," Senate President Bukola Saraki said in a statement, adding that he has "precipitated a constitutional crisis."

'Brazen dictatorial act'

Chief Justice Onnoghen was charged on 12 January with breaching a rule that public officials disclose foreign bank accounts.
He had secured a temporary injunction to h