The New Hampshire Attorney General's office and the Manchester Police Department are investigating police officers' use of force during a recent arrest.
Early Sunday morning, officers tasered two people and arrested four after a fight broke out at Bonfire, a downtown Manchester bar.
A video posted online shows the four police swearing at and tackling three men who appear to be resisting arrest.
In a statement Tuesday, a police spokesman said it is sometimes necessary to "use force when arresting a combative suspect."
The Manchester Police Department is reviewing the incident and Mayor Joyce Craig says the city is committed to getting all the facts.
Geoffrey Ward, Senior Assistant Attorney General and Chief of the Criminal Bureau, says he has "the utmost confidence" that the police review will be thorough.
Normally the Hillsborough County Attorney would investigate use of force after the police had finished its own review. But Ward says the County Attorney's office is under investigation for its handling of other cases and is transitioning leadership after the election two weeks ago, so the Attorney General's office will conduct the investigation instead.
Manchester police did not respond to an inquiry about whether the officers involved in Sunday's arrest have been placed on leave during the investigation.