Two British terror suspects have been reportedly killed in an attack by U.S. military drones, on the Pakistan-Afghanistan border.

The duo, identified as Ibrahim Adam and Mohammed Azmir Khan, died in the CIA-authored strike on Waziristan. Adam, 24, was said to be planning an attack on the UK.

Adam, from Barkingside in East London, was on the run from UK authorities after being placed under control orders in May, 2007. One of Britain's most wanted al-Qaida terror suspects, Adam is the brother of Anthony Garcia, who has been in jail (serving a life sentence) since 2007. Garcia was found guilty for his role in planting a fertilizer bomb to launch attacks on London and across the UK. In May 2007, the then home secretary John Reid, described Adam and his older brother, Lamine, as dangerous. The pair supposedly fled the UK on a flight to Pakistan,

Azmir Khan, from Sheffield, was under the scrutiny of a Treasury order in a case related to funding terrorism. Azmir Khan's brother, Abdul Jabbar, was also killed in a CIA drone attack in Pakistan, in September last year.

According to media reports, the two Britons actually died much earlier but news of their deaths was only recently conveyed to their families. It is reported that Adam was riding a motorcycle when he was hit; Azmir is said to have been killed two weeks later.

"We can confirm that we have heard our son has been killed in a drone strike," the Guardian quotes the emotionally-torn father of Adam, "We now wish to be left alone and grieve for our son." Adam's father also spoke about his belief that his son had been "executed" without having committed a crime.

According to official reports, Adam was part of an al-Qaida network in the UK that was led by Rashid Rauf - the mastermind behind concept of blowing up aircrafts using liquid bombs. Rauf was also killed in a drone attack, in 2008.

Though the UK did not consider the Adam brothers as a direct threat, MI5 had suspicions that Adam could be involved in a Mumbai-style terror plot to mount a gun attack on targets in the UK, the Guardian has reported.

Meanwhile, the Foreign and Commonwealth Office could not confirm Adam and Azmir's deaths but said it was investigating the reports.

"We are aware of reports and looking into them further," a statement said.