Police investigating three arson attacks on South Tyneside - two at schools - believe they may be linked.
Arson attacks have closed schools on South Tyneside
They also hope that they have found evidence from the more recent incident that could prove decisive in finding the culprits.
Two schools and a church in Jarrow, near South Shields, have all been extensively damaged over a three-week period.
Now officers from the Tyne and Wear arson task force say they are closer to tracing those responsible.
Dunn Street Infants School in Jarrow was set alight on 26 January.
The school had recently been saved from closure after a campaign by local parents.
On 10 February a nearby Baptist church was severely damaged by arsonists.
Six days later Springfield Comprehensive School, also in Jarrow, was hit by another arson attack.
A spokesman for Northumbria Police said: "We now believe these attacks are linked.
"They all have the same method of entry to premises and the fires were started in similar ways.
"We also have certain material found at the last attack at Springfield Comprehensive which could prove very important."