The US dropped more bombs and killed more civilians in Iraq and Syria in March than any other month on record, an independent monitoring group has said.

According to Airwars, a London-based non-for-profit which tracks the US air campaign against Isis, there has been "unprecedented" increase in the number of munitions dropped on both countries in recent months.

The group said that 268 strikes were carried out on Iraq and 434 were carried out on Syria within the month of March alone, killing at least 1,782 civilians and as many as 3,471.

Much of the fighting has been concentrated in Mosul in Iraq and on the outskirts of Raqqa in Syria, where the US coalition has been waging months-long campaigns in Isis.

But with fighting far from over in both cities, Alex Hopkins of Airwars said the devastation of the air campaign is only set to get worse.

"After a disastrous strike on 17 March claimed up to 230 lives in Mosul, media attention intensified and the coalition began reviewing its strike policies in the campaign there," he said.

"However, civilians were also killed in record numbers across the border in the vicinity of Raqqa, Syria. Indeed it appears highly likely that the coalition killed hundreds of civilians in Syria during March, with little press coverage.

"Neither the campaigns for Raqqa nor Mosul have finished – and coalition proxies backed by US forces have yet to even begin fighting in Raqqa city itself."

Between January and 31 March, Airwars said a total of 10,918 munitions were dropped in Iraq and Syria – a 59% increase than for the same period last year.

Some will see the steep rise in airstrikes as US President Donald Trump keeping his campaign promise to "bomb the s**t" out of Isis, whereas others have said it is a cheap attempt to win over support after a rocky start to his presidency marred with allegations of Russian collusion and a failed attempt to replace the healthcare bill known as Obamacare.

Writing for The Intercept, Glenn Greenwald said: "In every type of government, nothing unites people behind the leader more quickly, reflexively or reliably than war.

"Donald Trump now sees how true that is, as the same establishment leaders in US politics and media who have spent months denouncing him as a mentally unstable and inept authoritarian and unprecedented threat to democracy are standing and applauding him as he launches bombs..."

Airwars reported the unprecedented casualty rate as US forces dropped the biggest non-nuclear bomb ever used in a conflict in Afghanistan's Nangarhar province on Thursday (13 April). It follows a similarly spectacular strike on Syria's Sharyat airbase a week earlier.

Trump himself has previously demonstrated he believes that bombing other countries is a way to gain support in the polls.