In Kabul there are growing concerns over security after the shooting of five British soldiers by a rogue Afghan police officer amid claims that President Hamid Karzai’s government is illegitimate.Abdullah Abdullah, who pulled out of a presidential run-off vote, said Karzai’s re-election was unlawful but he is urging his supporters to remain calm. Afghanistan deserves a better administration than any Karzai is able to offer Abdullah said, but his expectation, he claimed, is for the people to exercise constraint and abide by the rule of law. The flawed election process has left Washington and Afghanistan’s other Western supporters working with a partner whose legitimacy has been questioned. Yesterday, an Afghan policeman shot dead five British soldiers at a checkpoint in southern Afghanistan. The three Grenadier Guards and two Military Police had been mentoring Afghan officers in a compound when one of their charges opened fire. Analysts believe the incident could undermine trust among security personnel at a time when the need for unity is paramount.