An assassination attempt on President Hamid Karzai by an al-Qaeda affiliate has been neutralized, Afghanistan's top intelligence agency said on Wednesday, DPA reported.
A group of six highly educated individuals linked to al-Qaeda had been arrested, the Afghanistan National Directorate of Security, the country's intelligence office, said.
"They planned very big things, and one of these acts was an assassination attempt on President Hamid Karzai," agency spokesman Lutfullah Mashal told reporters in Kabul.
The arrest comes less than three weeks after former president and top negotiator Burhanuddin Rabbani was assassinated by a suicide bomber in his well-guarded house.
Mashal named one of those detained as Mohibullah, a security guard in Karzai's protective service, along with five others.
"Another highly educated individual is Dr Emal Habib, head of the Microbiology Department at Kabul Medical University, who has been arrested with three university students and a Kabul resident," he said.
"They succeeded in penetrating the presidential palace protection team and recruiting one of the presidential guards," Mashal said.
He said Habib had links with a former Guantanamo Bay prison inmate and an Arab man living in the Waziristan in northern Pakistan.
"They had plans for terrorist activities in Washington DC and New York City," Mashal said.
High-ranking officials have been targeted by Taliban militants in recent months. Ahmad Wali Karzai, Karzai's half brother and head of the provincial council in southern Kandahar, was killed by one of his bodyguards in July.
Taliban militants have claimed responsibility for dozens of officials killed over the past two years.