Data lays bare the extent and geographical spread of attacks in Africa’s most populous country

Data from Acled and the Global Terrorism Index shows that after a few years of improvement, insecurity in Nigeria has worsened. With general elections less than a year away, the crisis has come under increasing scrutiny – both abroad and at home.

Experts say the primary long-term driver of insecurity is a governance vacuum across much of the country. On paper Nigeria is a federation comprising 36 states and 774 local government council areas, but in practice power is heavily centralised at the federal level. Resources trickle down to states in limited quantities and are distributed in far smaller amounts to local government councils, largely at the discretion of governors.

Donald Trump has fired his controversial US homeland security secretary, Kristi Noem, after weeks of bipartisan complaints about her leadership. As the public face of an aggressive immigration crackdown that prompted lawsuits and nationwide anti-ICE protests, Noem’s year-long tenure was plagued by multiple controversies, including accusing two US citizens killed by immigration agents of ‘domestic terrorism’. What exactly led to Noem’s firing and what do we know about her replacement? Nosheen Iqbal speaks to the Guardian US live news editor Chris Michael

A unit of Immigration and Customs Enforcement (ICE) agents will join a US delegation to the Winter Olympics in Italy, sparking confusion and uproar in the country.

Guardian reporter Jakub Krupa looks at what role the agency, which is embroiled in a violent US immigration crackdown, might have at the Milan-Cortina Games.

ICE said agents would 'vet and mitigate risks from transnational criminal organisations' but not run enforcement operations.

Milan’s mayor, Giuseppe Sala, said the the agents would be unwelcome in the city. 'This is a militia that kills,' he said

Warning: this video contains footage that may be distressing to some viewers

At about 9am on Saturday, US federal agents shot and killed Alex Pretti, a Minneapolis nurse who was observing immigration officers in the city. The Guardian’s video team has pieced together footage showing the attack from different angles

The Syrian government has taken control of several prison camps holding Islamic State (IS) suspects in the north-east of the country. The takeover took place after the Syrian Democratic Forces (SDF), which previously controlled the facilities, signed a ceasefire agreement with the government. Hundreds of prisoners reportedly fled the camps during fighting before the truce. Damascus claims to have recaptured most of the escapees, but the instability has reignited fears over the resurgence of IS in the region

• Concern over north-east Syria security amid fears IS militants could re-emerge