The trainers, believed to number about 20, were working with Pakistan's frontier constabulary - a paramilitary force on the front line of the fight against the Taliban and al-Qaeda.

The Ministry of Defence said it was due to "security concerns". But it added that the withdrawal was temporary.

The United States has already had to bring home more than 100 military trainers.

Pakistan is still smarting from the raid, which it views as at attack on its sovereignty, she said.