Two men will appear in Christchurch District Court today following at least two car bomb explosions.
Car fires in Bromley on May 14 and May 24 worried emergency services who feared people could be killed by gas cylinder "bombs" being planted in cars.
Recipes for the elaborate bombs have been
circulated on the internet, and police and the Fire Service have issued warnings to their staff after the explosions.
An industrial-sized LPG cylinder that exploded in a car on Tuesday night knocked out power to thousands of Christchurch homes.
There had been at least one other similar car arson involving a 45kg gas cylinder since March 14, according to an internal police memo.
"We are advised by the Fire Service that there is a blast radius of up to 100 metres. The safety zone that should be observed is 150 metres," the memo said.
"These cylinders used in this way effectively become a bomb. All (police) staff attending car fires should be wary and consider your safety and that of your partner/staff."
This week acting detective senior sergeant Mike Johnson said police had "grave concerns" about the methods used by the people in the two car arsons, which are believed to be linked.
"We will be dealing with these people (setting the bombs) seriously when we get hold of them and if someone gets injured we will be dealing with them appropriately."
The Fire Service sent a message to many of its Christchurch staff warning about the danger of "booby traps".
Christchurch deputy chief fire officer Greg Crawford said the tactics used were available on the internet and were "quite elaborate".
Mr Crawford said he had warned his staff and some volunteer firefighters to be conscious of the danger of the explosive set-ups.
Police said today that two men, aged 20 and 21, would appear in Christchurch District Court today in connection with the explosions.
- NZPA
