KABUL (AFP) - A surge in militant-linked unrest across Afghanistan left 28 people dead including four US soldiers killed in bomb strikes near the capital, officials said Monday. A 40-nation NATO-led force helping to fight a Taliban-led insurgency announced the deaths of four of its soldiers in a statement that did not give their nationalities. Four International Security Assistance Force (ISAF) service members were killed as a result of two improvised explosive device attacks in eastern Afghanistan today, it said. An ISAF official told AFP on condition oaf anonymity that they were American troops who were killed in Wardak province near Kabul. About 3,000 US troops moved into Wardak and Logar provinces, both strategic areas which adjoin the capital, early this year to combat growing insurgent violence. In other deadly attacks, Taliban stormed a police post near the northern town of Kunduz, where German and Belgian troops are based for ISAF. Four policemen were martyred when Taliban attacked the police post, Kunduz police chief General Abdul Razaq told AFP. The US military announced in various statements that its forces had killed 11 insurgents in separate air strikes and clashes in Wardak, Ghazni and Uruzgan provinces. Heavy clashes continued in the northwestern province of Badghis with Afghan troops killing five insurgents and wounding eight on Sunday, the army spokesman for western Afghanistan, Abdul Basir Ghori, told AFP. A rocket fired by the militants killed a woman and a shopkeeper the same day in the same district, he said. In another attack blamed on militants on Sunday, a roadside bomb killed an Afghan soldier in the eastern province of Paktya, the defence ministry said in a statement. Separately a school teacher was killed and one was abducted in an insurgent attack late Sunday in western Farah province, the Afghan education ministry said.