Crisis for US and Pakistani ties after troops killed

Pakistanis burn Nato and US flags in Multan yesterday in protest at the air strike (EPA)

The United States was struggling yesterday to contain the latest crisis in relations with Pakistan triggered by the killing on Saturday of 24 Pakistani soldiers in an apparent Nato airstrike near the border with Afghanistan.

As Pakistan blocked two key Nato supply routes to Afghanistan, Hillary Clinton, the Secretary of State, was among US officials contacting Islamabad to express regret and to try and patch up deeply damaged relations. The Nato Secretary General, Anders Fogh Rasmussen, supported an investigation launched by ISAF, the Nato-led international force in Afghanistan.

However, Pakistan's Foreign Minister, Hina Rabbani Khar, told Ms Clinton yesterday the strike negated all progress in improving the strained alliance between the two countries, and confirmed Pakistan expected the US to vacate Shamsi airbase, which is used for drone operations, within two weeks.

Brigadier General Carsten Jacobson, the ISAF spokesman, said it was "highly likely" Nato helicopters caused the deaths of the Pakistani soldiers. He said: "There was an operation on the ground in Kunar conducted by a combined Afghan and American force. A tactical situation developed on the ground resulting in an airstrike being called in."

With a border that is rugged and largely unmarked, the risk of fire being misdirected by accident is always present. A number of Afghan officials claimed the firing started from the Pakistani base, and the Nato helicopter was responding to an attack on its troops. However, there was widespread rage across Pakistan yesterday where sentiments towards the US have darkened since the raid that killed Osama bin Laden in May in a Pakistani garrison town, which was planned and carried out by the US without the knowledge of Pakistan's leaders.

An angry crowd of about a thousand people gathered outside the US consulate in Karachi. And much of the nation was gripped by live television coverage of the funerals of the soldiers killed in the strike. Lorries filled with supplies for Nato troops were also backed up at the two border crossings shut by the government at Torkham and Chaman.