The justice system is still reeling over a weekend of deadly attacks in the US, with at least 10 people killed and hundreds injured.
US Attorney General Loretta Lynch said there were no immediate charges in the attacks and there were still no suspects in the violence.
“There is no indication of any connection between the attacks or any connection to domestic terrorism,” Lynch said.
The attacks began on Saturday in Washington DC when a car was driven through a crowd of people outside a Republican Congressional baseball practice.
More than two dozen people were killed and more than 400 injured.
Six days later, a gunman shot and killed a police officer in Louisiana.
Two other officers were wounded in the attack.
More than 100 people were arrested in connection with the attack and two of the suspects have been identified.
On Sunday, a woman was shot and wounded outside a bar in Minneapolis.
Police said they found the body of the woman inside the car, which had a bloodied front bumper and a bullet hole in the driver’s side window.
Another person was arrested on Sunday night in Virginia.
A gunman opened fire at a concert in St. Louis on Sunday, killing nine people and wounding seven others.
In Cleveland, a man opened fire on police during a traffic stop and a suspect was killed, police said.
Another suspect is in custody.
Meanwhile, two other men were arrested and charged with shooting at officers in the parking lot of a hotel in St Louis.
At least one other person was injured during the weekend, authorities said, but they said the attack did not appear to be related to terrorism.
Lynch said in a statement on Monday that there had been a “tremendous increase in threats” in recent months.
‘We will get it right’ The FBI said on Sunday that it was continuing to investigate the attacks, and that authorities were “reviewing the actions of the police department.”
“We will not rest until the violence is stopped,” Lynch told reporters.
US President Donald Trump told reporters that the US had “done a lot better” than many countries in recent years to “get things done.”
He added that the government would work closely with Congress to ensure justice for those killed and injured.
“We are going to get it done,” Trump said.
“We will take care of the people that are being shot and they are going be shot back at us.”
Lynn said the US was still considering the extradition of three of the gunmen.
Earlier on Monday, US Secretary of State John Kerry said the United States was sending a message of “impartiality and respect” to the families of those killed in the deadly attacks.
“[We are] deeply saddened by the deaths of two young men and we are saddened by this horrific attack, we are deeply saddened that two innocent young men were shot and injured, we stand shoulder to shoulder with them,” Kerry said.
“The president is with them, and we will continue to stand with them as they continue to heal.”
Meanwhile in Washington, Lynch said US Attorney Generals Loretta L. Lynch and Dana Boente would be leading a review of how the justice system handled the attacks.
Lynch also said the FBI had launched a new investigation into whether anyone had been criminally charged in connection to the attacks in Virginia and Louisiana.