Image copyright Reuters Image caption At least 51 children were injured

A UN report has found that 30 children were killed and 51 injured in an Afghan air strike last month in the north-eastern province of Kunduz.

The government said after the strike on 2 April that its air force had targeted a gathering of senior Taliban figures

The investigation by the UN found six adults had also been killed in the air strike near a religious school, where an open-air ceremony was under way.

There were "credible" reports the final toll could be higher, it noted.

According to the UN report, hundreds of men and boys were attending the event in the Dasht-e Archi district when it came under rocket and heavy machine gun fire from helicopters.

The Afghan government initially said 18 senior militants planning an attack had been killed and accused the Taliban of shooting civilians.

However, a doctor who spoke to AFP news agency at the time said "all the victims" had been "hit by pieces of bomb, shrapnel" and not gunshots, as reported by the government.

The Taliban denied any militants had been present during the air strike and said 200 civilians had died or been injured.

The UN Assistance Mission in Afghanistan (Unama) said that while it could not confirm or deny the presence of Taliban fighters at the time of the air strike, it questioned "the extent to which the government undertook steps and concrete measures to prevent civilian casualties".

The report added that the high number of child casualties raised concerns over "the Government's respect of the rules of precaution and proportionality under international humanitarian law".

Investigators noted that residents felt "caught in the middle" of the conflict between the Afghan government and the Taliban.

Both the Afghan government and the provincial governor have launched their own investigations into the incident, though their findings have not yet been released.

Former Afghan President Hamid Karzai condemned the attack, saying at the time that "such raids, carried out in the name of fighting terrorism... are against all principles".

The number of air strikes carried out by Afghan and US forces has surged since a new strategy was announced by US President Donald Trump in August last year.

But the UN has noted an increase in civilian casualties as more air strikes have been carried out.

In 2017, the UN recorded 631 civilian casualties from air strikes by pro-government forces, including international military forces, a 7% increase on 2016 even though total civilian casualties decreased by 9%. More than half of the casualties resulted from operations carried out by the Afghan army.

It was the highest number of civilian casualties from air strikes in a single year since the UN started systematic recording in 2009.