At least 28 people were killed and dozens wounded by a blast inside an Afghan mosque during Friday prayers, officials said, a day after the United Nations said violence in the country had reached "unacceptable" levels.

At least 30 civilians were killed when the US bombed several drug-making facilities in western Afghanistan in May, a UN agency said in a report Wednesday, though the US military immediately disputed the findings.

The death toll from a massive Taliban bomb attack which flattened a hospital in southern Afghanistan earlier this week has risen to at least 39, officials said Friday.

The Taliban killed at least 10 people and wounded 90 Thursday after a car bomb targeting an intelligence services building exploded and destroyed a nearby hospital in the southern Afghan city of Qalat, the governor of Zabul province told AFP.

Taliban suicide bombers killed at least 48 people and wounded dozens more in two blasts Tuesday -- one at a campaign rally for the president and the other in Kabul -- with the insurgents warning of more violence ahead of elections.

A Taliban suicide bomber killed at least 26 people and wounded dozens near a campaign rally for Afghan President Ashraf Ghani on Tuesday, with the insurgents warning of more violence ahead of elections.

The Taliban on Tuesday vowed to continue fighting against US forces in Afghanistan after President Donald Trump said talks with the insurgents were "dead", saying Washington would regret abandoning negotiations.

The Taliban launched an offensive Friday against a key city in western Afghanistan, officials said, the latest in a surge of attacks as the US pushes for a deal that would allow it to begin withdrawing troops.

NATO "fully supports" American efforts to find peace in Afghanistan, the alliance chief said Tuesday after talks with US Secretary of State Mike Pompeo on a deal taking shape with the Taliban.

US Secretary of State Mike Pompeo headed to Brussels on Monday to discuss a proposed Afghan peace deal with the NATO chief and seek fresh engagement with new EU leaders after months of tensions.

An American service member was killed in Afghanistan, the US-led NATO mission said Friday, the latest US fatality as talks between the US and the Taliban continue.

US and Taliban negotiators are "at the threshold of an agreement" to end 18 years of conflict between them, Washington's top negotiator said Sunday as he concluded their latest talks.