Former soldiers Stuart Harness and Gavin Humphries, who fire-bombed a mosque in Grimsby following the murder of soldier Lee Rigby, have each been jailed for six years at Hull Crown Court.
Humberside Police have said they are considering the possibility that the "mosque was targeted for racial reasons," but stressed that it would not be fair to speculate on this at present.
They said there was was "no suggestion" of a link between two separate offences - a fire at the mosque last night, and reports of youths damaging the building on Thursday.
Humberside Police have made a total of 13 arrests following incidents at a mosque on Weelsby Road in Grimsby, Lincolnshire.
Two men, aged 33 and 37, remain in custody after they were arrested in connection with a fire at the mosque on Sunday night.
Another 11 individuals were arrested last Thursday following reports of youths damaging vehicles and the Mosque.
Six of those people have been released without charge, and four 16-year-old boys and a 15-year-old boy have been released on bail until the end of June.
The Mayor of North East Lincolnshire Peggy Elliott has condemned an alleged arson at a mosque in Grimsby.
"I can't believe people in the community would do such a thing but they are in the minority."
Councillor Peggy Elliott.
Police came across the fire at the Islamic Cutural Centre on Weelsby Road around 10pm last night. The fire was put out and no one was injured. Police say it is too early to speculate on the cause of the blaze. Two people have been arrested in connection with the incident.
Footage released by the Grimsby Telegraph shows the aftermath of the arson attack on he Grimsby Islamic Cultural Centre last night.
The centre was targeted while police officers were guarding it, following an incident last week when bricks were thrown through its windows.
Grimsby MP Austin Mitchell said attacks on mosques and other Islamic institutions were playing into the hands of terrorists who wanted community conflict.
Mr Mitchell told BBC Radio Humberside: "It's sheer, simple stupidity. I'm appalled and shocked. I didn't expect this in Grimsby.
A mosque chairman has spoken of the petrol bomb attack on the Grimsby Islamic Cultural Centre last night.
Diler Gharib was inside the centre with a young family when it was targeted by arsonists.
He told the Grimsby Telegraph: "We had just finished our prayers and were discussing how to thank our neighbours for the support they have shown us over the past few days when we heard a bang and saw fire coming under the door."
Two people have been arrested following a fire at an Islamic cultural centre in Grimsby, Lincolnshire, police said.
The funeral of the family killed when their car collided head on with a lorry near Grimsby will take place today.
Forty-eight-year-old David Cockburn and wife Angela, 48, were driving with their daughters, 21-year-old Carly Cockburn and 18-year old Bethany Cockburn to a dancing competition at Butlins, in Skegness.
Both of the girls had won dozens of trophies in freestyle dance contests, Bethany's daughter, Lacey Jade Stephenson was also in the car at the time of the crash.
Police are still investigating what happened on April 12 when the family's Nissan Primera hit a light goods vehicle.
The service will take place at St Johns Church, in Birtley, Gateshead, at noon, followed by committal at Saltwell Crematorium.