Growing fear of reprisals after US soldier kills 16 civilians in 3am shooting spree

Distraught and furious Afghans vowed vengeance yesterday after a US soldier apparently walked off a Nato base into civilian homes, turning his weapon on the families inside and killing 16 people, nine of them children.

The Afghan Ministry of Interior has urged people to show restraint until investigators have completed their inquiry, but the killing spree deepens a crisis between US forces and their Afghan hosts. Concerns are mounting that the incident will re-ignite violent protests that swept Afghanistan last month after US servicemen burnt copies of the Koran at Bagram Air Base.

American officials were swift to try to limit the damage, with the US commander in Afghanistan, General John Allen, issuing a statement pledging a "rapid and thorough investigation" with anyone found to have committed wrongdoing to be held "fully accountable". President Barack Obama called the attack "tragic and shocking".

Nazim Shah returned to his home in Panjwai district to find his entire family killed. Sobbing into the phone, he told i: "All my family is dead... We will get revenge on those who killed my family. We won't let this rest." The attack comes at a crucial time, as President Hamid Karzai and US officials, under strained relations, negotiate a future role for foreign forces after Nato troops hand over security to Afghans in 2014.

Witnesses and officials gave differing accounts of yesterday's events, but it appears that the soldier, as yet unnamed, left the joint US-Afghan Zangebad base at about 3am. He walked to the villages of Balandi and Alkozai, about a kilometre away, and began the killings, which left nine children, three women and four men dead. Five more were wounded.

"The US soldier attacked three houses, killing 11 people in the first, four in the second house and one in the third," said Mahammad, a tribal elder in Panjwai. "The 11 people who were first shot dead were brought together in one home and the soldier put pillows, sticks and blankets on them and burnt them."

General Carsten Jacobson, spokesman for the Nato-led International Security Assistance Force, confirmed that the soldier gave himself up.