Police have opened more than 500 lines of inquiry into an explosion at a County Donegal service station that killed 10 people.
More than 260 statements have also been taken since the blast in Creeslough on 7 October.
The victims – four men, three women, two teenagers and a five-year-old girl – were from the village or surrounding areas.
Police have previously said the incident appeared to be a tragic accident.
In a statement issued on Thursday evening, gardaà (Irish police) said door-to-door enquiries were ongoing as part of the investigation, with interviews carried out daily.
A large amount of CCTV footage is also being examined and a company specialising in the investigation and testing of energy systems remain on site, according to the statement.
This investigation is being co-ordinated from Milford Garda station.
An Garda SÃochána (the Irish police force) said the preservation of the scene will be extended until 27 November, after an application was made to the High Court.
The road through the village will also remain closed.