A police officer was killed and another injured on Friday after a car crashed into a barricade outside the United States Capitol complex in Washington DC, AFP reported. The driver was shot dead by the police after he got out of the car and tried to attack them with a knife.

Washington Metropolitan Police Chief Robert Contee told the news agency that the incident did not seem to be terrorism-related, but investigation into it would continue.

US President Joe Biden said he was heartbroken by the death of the police officer, Reuters reported. The White House said that the president had been receiving updates about the incident as investigation progresses. “Jill [Biden] and I were heartbroken to learn of the violent attack at a security checkpoint on the US Capitol grounds,” the president said in a statement.

Following the attack, the Capitol complex went under a lockdown, less than three months after a mob attacked the building and clashed with the police.

On January 7, hundreds of supporters of former US President Donald Trump stormed the Capitol complex as members of the Congress met to certify the results of the 2020 presidential elections, which Biden won. Five people died in the violence. At least 68 were arrested.

The incident triggered shock across the world. Several White House officials tendered resignations following the incident, while the demands for Trump’s removal from the top office grew.

After the violence, Trump conceded defeat to Biden. For months, he peddled election conspiracy theories and claimed that the presidential poll had been rigged.

Trump was impeached for a second time on the charge of “inciting the insurrection, but was acquitted by the Senate in February.