Sources close to the National Grid have confirmed that multiple autonomous drones were detected operating within restricted airspace near critical infrastructure sites over the past 72 hours. The incidents, which remain classified, have triggered an urgent review by the Joint Terrorism Analysis Centre (JTAC).

According to two government insiders who spoke on condition of anonymity, the drones displayed sophisticated navigation capabilities, avoiding standard countermeasure systems. One source described the incursions as 'a new level of threat' that challenges current security protocols.

'The drones weren't just flying. They were mapping. They were learning,' said a former RAF drone operator with knowledge of the pattern. 'This isn't hobbyists. This is reconnaissance.'

The National Grid has declined to comment, citing operational security. However, internal memos obtained by this journalist reveal that energy sector watchdogs have been placed on heightened alert. One note reads: 'Presence of unidentified autonomous systems near substations represents a credible risk to continuity of supply.'

The Ministry of Defence confirmed that 'defensive measures were deployed' but refused to elaborate on whether any drones were neutralised. A spokesperson for the Civil Aviation Authority stated that an investigation is underway, though they would not confirm the number of incidents.

This follows a pattern of increasing drone activity near sensitive sites across the UK. Last month, a separate alert was issued after a quadcopter was spotted near a nuclear facility in Cumbria. But these new incursions are different. The drones were not commercial off-the-shelf models. They were custom-built, with encrypted communication links and the ability to operate in GPS-denied environments.

A defence analyst, who has previously advised the Home Office, told me: 'This is exactly how you'd map a target for an electromagnetic pulse attack. Or to identify the exact layout of primary substations to cause cascading failures.'

The timing is also troubling. The incursions coincide with a surge in cyber attacks against energy companies. Sources suggest that these physical reconnaissance flights could be paired with digital intrusions to create a multi-vector assault.

'We're looking at a coordinated effort to probe vulnerabilities,' said a former GCHQ intelligence officer. 'The question isn't if they'll strike, but when.'

So far, no group has claimed responsibility. But the sophistication points toward state-sponsored actors. The Home Secretary has been briefed, and a cross-departmental task force is meeting daily.

Meanwhile, the public remains in the dark. The government has not issued any warning to energy companies beyond a confidential bulletin that was circulated last Thursday. This is not good enough. We are sleepwalking into a crisis.

I have seen the flight logs. The drones came within 200 metres of a major substation that supplies power to a quarter of London. If those logs are correct, someone knows exactly where to hit.

The question for Number 10 is simple: why aren't they telling us?