Vandals damaged and overturned around 100 Jewish gravestones in Philadelphia, United States, Reuters reported on Monday. The incident follows a series of bomb threats and attacks on Jewish sites across the country. Last week, 170 headstones were damaged at a Jewish cemetery in St Louis.

Local media, however, pegged the numbers of damaged gravestones at more than 500, AFP reported. A local rabbi told ABC television affiliate WPVI that some of the graves were more than 100 years old.

“We just have to find out if it’s drunken kids or an act of — well, it is a predominantly Jewish cemetery, so we have to look into that fact,” said Jim McReynolds, a detective for the Philadelphia Police Department, The Washington Post reported.

A watchdog group, the Anti-Defamation League, has announced a $10,000 (approximately Rs 6.6 lakh) reward in the case, police said.

The Anne Frank Center urged US President Donald Trump to make a national address specifying how his administration plans to tackle rising anti-semitism and Islamaphobia. Israel’s foreign ministry spokesperson, Emmanuel Nahshon said he had full confidence the US government would “catch and punish the culprits”.

Muslim activists initiated a crowdfunding campaign to raise more than $100,000 (approximately Rs 66 lakh) to repair the Missouri cemetery, AFP reported.

Critics of US President Donald Trump say his election has encouraged anti-Semitic groups to increase their attacks on the community. Despite his denial of links to white nationalists, Trump’s campaign has received support from some of the most violent right-wing groups and white supremacists.

After the bomb threats, Trump had said these were “horrible and are painful and a very sad reminder of the work that still must be done to root out hate and prejudice and evil.” However, Trump was criticised for not making any reference to Jews killed in Nazi-run camps in his International Holocaust Remembrance Day speech.