Twitter has removed a post by Nigeria’s president Muhammadu Buhari that threatened a violent crackdown on unrest in the country’s south-east, referencing the civil war of the late 1960s that left more than 1m people dead in the region.

“Many of those misbehaving today are too young to be aware of the destruction and loss of lives that occurred during the Nigerian Civil War,” Buhari wrote on Tuesday in the now-removed post. “Those of us in the fields for 30 months, who went through the war, will treat them in the language they understand.”

Twitter said the statement had violated its abusive behaviour policy, which prohibits “content that wishes, hopes, promotes, incites, or expresses a desire for death, serious bodily harm or serious disease against an individual or a group of people”.

The post quoted comments that Buhari made during a meeting at which the head of the country’s electoral commission testified about a rise in attacks on electoral offices in south-east Nigeria. Violence has surged in the area in recent months, with authorities blaming the banned secessionist Indigenous People of Biafra group for torching police stations and sparking a prison break in April in which 1,900 inmates escaped.

The president warned that “whoever wants the destruction of the system will soon have the shock of their lives”.

Buhari is the latest head of state to have his posts removed by Twitter. Former US president Donald Trump was banned from the site for spreading disinformation about last year’s election, which he lost, and inciting his supporters to storm the US Capitol on January 6.

Buhari, an ex-general who ruled as a military dictator in the early 1980s, cut his teeth in the 1967-1970 Biafran war, as the civil war is also known, a brutal conflict that led to the starvation of more than 1m Biafran people.

The resurgent separatist movement and rising violence in the south-east, including armed gangs killing police officers, is just one of half a dozen security crises affecting Africa’s most populous country.

It is also confronting the decade-old jihadist Boko Haram insurgency in the north-east, violent clashes between nomadic herders and farmers, piracy in the Gulf of Guinea and a kidnapping-for-ransom crisis centred in the north-west but prevalent in every corner of the country.

As the security situation has deteriorated across Nigeria, Buhari has seen his national security credentials, which he ran on in 2015 and 2019, crumble. He has promised that with fresh leadership of the armed services and police, the situation will improve.

However, a main driver of the insecurity is the slowing economy, which is marked by soaring inflation, sluggish growth and rampant unemployment.