Police examine online activity
Chief Superintendent Marcus Noden said videos of the damage were circulating widely, prompting comments and discussions and helping people spread the message between areas. Specially trained officers are examining the posts, he told BBC Radio Manchester.
The attacks have affected houses in multiple occupation, known as HMOs, as well as buildings mistakenly believed to be HMOs. Police recorded damage at 41 properties in Salford, three in Tameside and two in Stockport.
Noden described the attacks as "unlawful, reckless and putting lives at risk". Addressing people encouraging them online, he said: "Stop what you are doing - lives are being put in danger".
Police are also examining possible connections to far-right anti-asylum groups, according to LBC, which reported that most of the incidents are believed to have a racial or religious motivation.
The Manchester Evening News reported that Ashlea Simon, a former co-leader of the far-right group Britain First and now a member of the anti-immigration group All For England, had posted YouTube "tours" through Kersal streets, claiming migrants were living there. Some HMOs shown in the videos were subsequently vandalized, the newspaper reported.
LBC reported that HMOs have become associated with migrant housing in recent months as the government pushes to move asylum seekers from hotels into community accommodation.
Homes targeted in Salford and Stockport
The Salford incidents included an attack on a family home on the evening of October 13: a severed pig's head was left outside and the family's front window was smashed, according to LBC and the Manchester Evening News. Graffiti on properties included "SEND THEM BACK" and "Stop the boats".
In its October 18 report, the Manchester Evening News described several of the homes targeted. One was understood to belong to young women, most of them nurses with the National Health Service and care workers. Another was a family home believed to be occupied by a white man from Salford and his brother. A flat where young Sudanese refugees who had fled genocide lived was also among the targets.
In Heaton Norris, near Stockport's town center, two properties were marked with anti-HMO graffiti last week, the Local Democracy Reporting Service reported. A window at one of them was then smashed on Tuesday.
Contrary to claims circulating on social media, neither Heaton Norris property is currently an HMO. One is understood to be on the market. The owners of the building with the broken window are seeking Stockport Council's permission to turn it into an eight-bedroom HMO. An owner, who asked not to be named, said the intended residents would be young professionals if the application was approved.
Arrests and suspected exploitation of children
Investigators arrested a 33-year-old man on Wednesday morning on suspicion of conspiracy to commit criminal damage. He remained in custody for questioning. Two other men, ages 46 and 39, had been arrested on Monday on suspicion of the same offense and were released on bail.
Police say evidence points to children being criminally exploited in connection with the attacks. A 13-year-old boy had previously been arrested.
Noden said police were treating the damage extremely seriously and continuing to pursue those responsible, including people suspected of using children to organize the offenses. He said he hoped the arrests would show that anyone involved would face consequences.
Council plans events to address misinformation
Salford City Mayor Paul Dennett urged unity, saying there was "no place for hate, violence, intimidation, or discrimination" in the city, LBC reported.
Salford Council said it was working with landlords and would organize events in affected communities to counter misinformation, according to the Manchester Evening News. Councilor Barbara Bentham, the council's deputy leader and community safety lead, appealed for calm.
Noden acknowledged residents' concerns about the damage spreading across Greater Manchester. Police have asked anyone with information that could help the investigation to contact them.
