Police in Greater Manchester are under "real strain" in the wake of the city's suicide bombing after the loss of nearly one in four officers in recent years, the force's chief constable has said.
Ian Hopkins cited official figures which show Greater Manchester Police (GMP) - currently carrying out one of its biggest-ever investigations - had 8,148 officers in March 2010, but this had dropped by 23% to 6,297 by March last year.
Writing on Twitter, he praised his officers for their "outstanding" work policing the Parklife festival over the weekend along with a protest against Islamist terrorism.
He wrote: "Outstanding from @gmpolice officers & staff this w/e policing protest & Parklife. Real strain on everyone not just this weekend ... see below."
Under his tweet, he posted a page from the HM Inspectorate of Constabulary (HMIC) 2016 efficiency report for GMP, with a table setting out staffing statistics.
It shows GMP's total workforce fell by a fifth during the period, from 13,189 to 10,506, while the number of community support officers (PCSOs) reduced from 842 to 748 - a drop of 11%.
The table shows these are set to fall even further over the next three years, with the total workforce expected to be 10,108 by March 2020 with 500 PCSOs.
Manchester mayor Andy Burnham tweeted: "@gmpolice are stretched to limit & in middle of on-going investigation."
He criticised the protest against Islamist terrorism, organised by former English Defence League (EDL) leader Tommy Robinson, which drew a counter-demonstration.
"These EDL-types who came today need to have a look at themselves," Mr Burnham added. "@gmpolice deserve better.
"I care about our police being unnecessarily distracted when they are worn out & still working hard to investigate a major incident."
The force, the second largest in England, is investigating the Manchester Arena suicide bombing which left 22 people dead and more than 200 injured.
The figures show GMP will lose more staff than the national average, with the total workforce forecast to drop by 24% between 2010 and 2020, compared with 21% across England and Wales.
About 400 officers were deployed to police Sunday's protest and officers made eight arrests for public order offences.
Chief Superintendent John O'Hare said many officers who had already worked long hours had to operate in "extremely challenging circumstances".
More than 1,000 officers have been involved in the investigation into the May 22 attack, with hundreds of witnesses interviewed and thousands of hours of CCTV being examined.
GMP said there are now more than 8,000 entries on its logging system and 700 media devices such as mobile phones have been seized.
A total of 29 houses have been searched and 22 people arrested during the inquiry, with all now released without charge.
Policing cuts also became a key issue of last week's general election, with Labour leader Jeremy Corbyn calling for Theresa May to resign as Prime Minister for presiding over cuts in police numbers as Home Secretary.
The topic came under the spotlight following the Manchester bombing along with London's two terrorist attacks, with Mr Corbyn slamming Mrs May over Government cuts which have left the police with 20,000 fewer officers than in 2010.