Different types of violence are commonly linked with large urban areas, often presumed to scale superlinearly with population size (i.e., to be disproportionately higher in larger cities).

This study explores the hypothesis that smaller, isolated cities in Africa may experience a heightened intensity of violence against civilians.

It aims to investigate the correlation between the risk of experiencing violence, a city’s size and its geographical isolation. Between 2000 and 2023, incidents of civilian casualties were analysed to assess lethality in relation to varying levels of isolation and city size.

African cities are categorised by isolation (measured by the number of highway connections) and centrality (the estimated frequency of journeys).

We show that violence against civilians exhibits a sublinear pattern, with larger cities witnessing fewer events and casualties per 100,000 inhabitants. Individuals in isolated cities face a fourfold higher risk of becoming casualties compared with those in more connected cities.

R. Prieto-Curiel, R. Menezes, Violence, city size and geographical isolation in African cities, Nature Communications 16 (2025) 10049.