Western embassies in the Nigerian capital Abuja on Monday advised citizens in the country to restrict their movements as the risk of what they called a “terrorist attack” has increased despite calls from the authorities to remain calm.

It was unclear whether the assessment from the US, UK and other countries was based on a new threat or on incidents that had already occurred.

Insurgents linked to the Islamic State group have claimed multiple attacks in states around the Federal Capital Territory (FCT) over the past six months, making many in the city of six million nervous.

On Sunday, the United States Embassy in Nigeria warned its citizens of an “increased risk of terrorist attacks in Nigeria, particularly in Abuja,” without giving further details.

“Avoid all non-essential travel or movement,” the statement said, adding that “services will be reduced until further notice.”

The UK, Canada and Australia issued similar warnings over the weekend, recommending citizens in Nigeria, and particularly Abuja, to avoid public places where crowds gather.

The statements also recalled that schools have been targets of Nigerian insurgents in the past.

In response, Nigeria’s State Security Agency, known as the Department of State Services (DSS), “recommended that the necessary precautions be taken by all.”

However, DSS spokesman Peter Afunanya said there had been similar warnings in the past.

“The service calls for calm as it works with other law enforcement agencies and stakeholders to maintain peace and order in and outside Abuja,” he said.

FCT residents, including Western diplomats, are increasingly concerned about insecurity after a mass breakout from Kuje Prison, a prison on the outskirts of the city, in July.

The incident, in which more than 400 inmates escaped, including dozens of suspected jihadists, prompted President Muhammadu Buhari to say he was “disappointed” with his intelligence services.

The police and military said they have been beefing up security in and around the city, which is surrounded by mountainous and forested areas and is difficult to patrol.

Jihadists in Nigeria generally operate in the northeast of the country, far from the capital, although they have small cells in other parts of the country.

The last time one of the groups – Boko Haram – attacked the city center was in 2014.

One of former army general Buhari’s key campaign promises in 2015 was to end insecurity, but violence has continued and spread under his watch.

On October 12, a man was killed in an attempted kidnapping by criminals in Abuja’s affluent Maitama neighborhood, where many Western embassies are located.

In addition to the terrorist threat, the capital is also surrounded by states with high levels of banditry – gangs of heavily armed criminals who kidnap and kill.

Analysts have warned that uncertainty could deepen as the political campaign to replace Buhari begins next year.