London, Aug 27 : British Prime Minister Boris Johnson said on Thursday that Britain will continue its evacuation operation at the Kabul airport despite twin bombings there that reportedly have killed at least 60 people. "I want to stress that this threat of a terrorist attack is one of the constraints that we've been operating under in Operation Pitting, in the big extraction that's been going on, and we've been ready for it; we've been prepared for it," Johnson told the reporters after an emergency meeting, Xinhua reported. "And I want to stress that we're going to continue with that operation -- and we're now coming towards the end of it, to the very end of it, in any event," he said. Two explosions took place at the Kabul airport on Thursday night, reportedly caused by suicide bombers. At least 60 people were killed and 140 others wounded in the explosions, the BBC reported, quoting a senior health official in Afghanistan. "Clearly, what this attack shows is the importance of continuing that work in as fast and as efficient manner as possible in the hours that remain to us, and that's what we're going to do," the prime minister said, noting that Britain "will keep going to the last moment." Less than a week is left for the US-led forces to evacuate from Afghanistan. During a Group of Seven (G7) virtual summit on Tuesday, Johnson and leaders of other US allies failed to persuade US President Joe Biden to extend the August 31 evacuation deadline. Johnson said earlier during the day that around 15,000 people -- the "overwhelming majority" of those eligible to come to Britain -- had been evacuated by the British troops. /IANS