Hamilton said the "main line of inquiry" was that the bomb had been planted by a group known as the New IRA.
The police confirmed in their statement that at least two armed men hijacked a pizza delivery vehicle and installed a bomb inside, which was then driven to the location before it was detonated.
A pizza delivery van was hijacked by two armed men in Derry at about 18:00 GMT (7am NZT).
In a statement on Facebook, the PSNI said that while no one was believed to be injured, "there is another auto we are not happy about".
The road remains taped off by police as they continue to investigate, but no arrests have been made.
"The goal of groups such as the New IRA is to highlight the fact that they are still here and are not going anywhere", said Marisa McGlinchey, the author of a forthcoming book, Unfinished Business: the Politics of "Dissident" Irish Republicanism.
Naomi Osaka wins an impossible match in the Australian Open 3rd round
Though she's yet to capture a Grand Slam title, Keys has recently been remarkably consistent at the year's biggest tournaments. Then the Japanese failed to serve out the set, and that was the moment that something broke in her performance.
Derry Sinn Féin MP, Elisha McCallion called on anyone with information about the attack to pass it on to police.
Currently, the police are working at the site of the emergency in Northern Ireland's city of Derry.
Officers evacuated homes and cordoned off both areas as they inspected the vehicles.
Sky News' senior Ireland correspondent David Blevins said the sound "would have been hauntingly familiar to people in the city", which is just two miles from the border with Ireland. "Perpetrated by people with no regard for life", she said.
"I know this second security alert and the measures we are taking to keep people safe will cause significant inconvenience for the local community, but we have no choice". The nationalist fight was spearheaded by the Irish Republican Army (IRA). It said the device was highly unstable and could have detonated at any time.
SDLP Foyle MLA Mark H Durkan said that he was told that the driver of the vehicle had been asked to take the van with a package that had been placed in it into the city centre.
President Trump visits MLK memorial
NCRM reported earlier Monday that for the second year in a row, and unlike all his predecessors since Martin Luther King, Jr . The Reverend Al Sharpton speaks during the National Action Network Breakfast on January 21, 2019 , in Washington, D.C.
He said the device "has not been as effective as they would have wanted for it to be".
Hamilton said: "Around three minutes later a phone call went in to the Samaritans in West Midlands in England, which was then passed to West Midlands Police who then contacted us".
Hamilton condemned the bomb attack as "unbelievably reckless".
Northern Ireland Secretary Karen Bradley told MPs that the weekend bomb blast on Bishop Street, which caused no injuries, had "absolutely nothing to do with Brexit".
Tánaiste Simon Coveney said the incident was a "terrorist attack" while SDLP leader, Colum Eastwood said those responsible represented no-one.
Le cuisinier aveyronnais Sébastien Bras étoilé… malgré lui !
Aussi, nous avons appris avec étonnement que nous réapparaissons dans le guide 2019 (avec 2 étoiles). La nouvelle édition du Guide Michelin pour la France sera en vente dès le 25 janvier.