The head of Nigeria's army on Wednesday vowed a violent crackdown on election-related unrest, as security tightened before this weekend's presidential and parliamentary vote.

Lieutenant General Kenneth Minimah said the armed forces, police and other organisations had made "adequate arrangements" for security at this Saturday's poll.

Bloody election-related violence has been a major concern at previous votes in Nigeria, especially between supporters of rival political parties.

In 2011, around 1,000 people were killed in clashes after Goodluck Jonathan's victory over Muhammadu Buhari for the presidency.

Minimah said heightened security would be in place both for the presidential and parliamentary vote on Saturday as well as on April 11, when gubernatorial and state assembly elections are held.

"I do not envisage any issue because this is just an election and it will come and go," he told a news conference.

"Though we know there are also elements within the political class that would not want a normal election process to come and be put behind us.

"I will appeal to politicians and their followers and supporters to keep the peace, maintain the peace and ensure a violence-free elections... and whoever wants to invoke or provoke violence will meet organised violence waiting for him."