Police say they were forced to close part of Douglas promenade on Saturday.
In the early hours, officers were called to an address on Central Promenade because of an incident.
A 22 year old local man was arrested and is currently helping police with enquiries.
No further details have been released.
Campaign group brands Summerland inquest decision 'deplorable'
'Our pursuit for justice continues'
No new evidence to justify fresh inquests, says Attorney General in Summerland ruling
Decision follows campaign by victims’ families and lawyers who argued the original inquests were flawed and key evidence overlooked
Attorney General declines application for fresh Summerland inquests
Prolonged campaign has sought to re-open case
Mountain Road closed following road traffic collision
Anticipated to remain shut until approximately 7pm