The attack on the Manchester synagogue raises deep questions about community relations in the UK, Home Secretary Shabana Mahmood said.
She warned that there were “malign and dark forces running amok across our country”, with antisemitism and “other forms of hatred” on the rise.
Four people arrested in connection with the Manchester attack remain in custody after police were granted extra time to question them.
Three men are still in hospital after the car and knife attack at the Heaton Park Hebrew Congregation Synagogue in Crumpsall, on Thursday.
Jihad Al-Shamie, 35, who was on bail for an alleged rape, was shot dead by police as he targeted the place of worship on Yom Kippur, the holiest day in the Jewish calendar.
Adrian Daulby, 53, is believed to have been shot dead by police while trying to stop Al-Shamie from entering the synagogue during the attack.
He died alongside Melvin Cravitz, 66, from Crumpsall, a worshipper who helped prevent the attacker from entering the premises.
The Home Secretary acknowledged that the Jewish community had repeatedly warned about the dangers they faced.
She told the BBC’s Sunday with Laura Kuenssberg: “I am, of course, as devastated as anyone else at what has happened here in Manchester on Thursday – feel tremendous grief for not just the people of our Jewish community, but for our national community as well.
“I am very worried about the state of community relations in our country. I know I, as the Home Secretary, have a responsibility to think about the action the Government can take to strengthen our communities, to make sure people are well-integrated into our society.
“That is a bigger piece of work for us to do, but I do recognise the sense of people feeling let down. I do recognise that people have been saying for a while that this was only a matter of time.
“It is devastating to hear our citizens say that and I will ensure that the Government response to what has happened meets the scale of the challenge that is being put to us.”
On Times Radio she acknowledged there are “wider, societal issues around the pace of migration and integration” but “I don’t think we should elide those additional issues into what we’ve seen happen here in Manchester”.
She added: “We have a broader problem of a rise not only in antisemitism but in other forms of hatred as well.
“There are clearly malign and dark forces running amok across our country.
“It’s a challenge for governments of all stripes to work out how to deal with these issues without placing more pressure, and frankly more unwanted burden and responsibility, on minority communities.”
The police operation is being led by Counter Terrorism Policing North West (CTPNW). They were granted the warrants on Saturday, meaning they can detain four people, whom they arrested on suspicion of preparing terrorist acts, for a further five days.
The warrants are in relation to two men, aged 30 and 32, and a woman, 61, all arrested in Prestwich, and a 46-year-old woman arrested in Farnworth.
Two other people, an 18-year-old woman and a 43-year-old man who were arrested in Farnworth, were released with no further action on Saturday night.
A Greater Manchester Police (GMP) statement said the investigation was “continuing at pace” with “significant resources” mobilised in order to “establish the full picture into what has happened”.
On Saturday, the force said three men remain in hospital with serious injuries, including a security guard with car-impact injuries and a Community Security Trust (CST) worker with stab wounds.
On Friday, the police watchdog, which is investigating the incident, said it was examining the use of lethal force by GMP firearms officers.
The investigation would include “whether police may have caused or contributed to the death” of Mr Daulby.
A GMP spokesman said they had increased patrols to reassure the community.
Conservative Party leader Kemi Badenoch was joined by Greater Manchester Mayor Andy Burnham and Assistant Chief Constable John Webster as she visited the synagogue on Saturday.
Mrs Badenoch has said Jewish people in the UK must be given greater security as some are “leaving to go to Israel”.
She said: “Israel is at war. How can people be leaving the UK to go to a war zone and think that they’ll be safer there?”
