Hertfordshire Police believe the incidents are race-related.

Syedd Shareef, from the Muslim Community Centre, said the first the first incident of vandalism had caused £4,000 in damage.

Windows were broken at the mosque

"After that, our windows were vandalised", he said.

He said thousands of pounds will be spent to improve security, including doors reinforced with cast iron, a steel fence, and CCTV.

Ade Osoba, a police officer specialising in race and hate crimes, said the vandals do not represent the opinions of the community.

"Stevenage itself is quite a nice town.

"I think most people would accept the mosque being here, but I think there's a small minority which have got strong feelings against it."

The mosque is due to open in December.