Pakistan’s intelligence agency said it has foiled a planned suicide bombing in Islamabad by Tehrik-e-Taliban Pakistan (TTP), involving an Afghan militant trained across the border.

In a statement Tuesday, security officials said a TTP cell intended to use a car bomb on Defence Day, set for 5 September. They said an operation on the outskirts of the capital led to the arrest of a senior TTP commander, the Afghan suicide attacker and five other militants accused of planning the attack.

Officials said the Afghan bomber had received training at the “Al-Farooq Fidayee” camp in Afghanistan. The group had rented a house in Tarnol, outside Islamabad, to use as a hideout, and had conducted reconnaissance in parts of the city in July to select targets, according to authorities.

Security officials warned the planned assault could have mirrored a deadly TTP attack in March on a military zone in Bannu, Khyber Pakhtunkhwa, when militants used a car bomb and a coordinated assault in an attempt to breach a secure compound.

The Pakistani army said Afghan nationals took part directly in that operation, which left 34 people dead, including five soldiers, 13 civilians and 16 TTP fighters, among them four suicide bombers. Another 32 people were wounded.