Taliban fighters attacked the northern Afghan city of Kunduz overnight, entering urban areas and threatening a repeat of the assault in which they seized the city exactly a year ago.
A roadside bomb killed a US soldier in Helmand, a province in southern Afghanistan that has seen an upsurge in violence in recent weeks.
Taliban insurgents, seeking to force the Nato-led coalition out of Afghanistan and bring in Islamic law, captured a key district in the northern province of Baghlan after days of fighting, officials said on Monday.
Fighting raged on Thursday in Helmand after Afghanistan rushed military reinforcements to beat back Taliban insurgents advancing on the besieged capital of the southern poppy-growing province.
Fierce fighting in Helmand has sent thousands of Afghans fleeing to the capital of the southern opium-rich province, sparking a humanitarian crisis as Taliban insurgents besiege the city despite intensified US air strikes.
Afghanistan faces the risk of a new spiral in violence following a series of attacks on civilians in the last few months but on the battlefield, security forces have been holding their ground, a UN official said.
Taliban on Tuesday kidnapped around two dozen people after pulling them off buses in southern Afghanistan, officials said, the latest in series of abductions on the country's increasingly dangerous highways.
Hundreds more US troops are headed for Afghanistan's strife-torn Helmand province to shore up security forces who have struggled in the face of sustained Taliban attacks, officials said.
A US soldier has become the first American killed in Afghanistan in 2016 while two more were wounded in an operation in Helmand province, where Afghan troops are battling Taliban insurgents.
