Police officers wounded in knife attacks in Brussels and London

Belgian soldiers shot a man dead near central Brussels Friday evening after he came at them with a knife shouting "Allahu Akbar (God is great)" in a case authorities are treating as a terrorist attack.

The man, a 30-year-old Belgian of Somali origin, died after being rushed to hospital. The soldiers were not seriously hurt in the attack; one had a facial wound and the other's hand was cut.

Prosecutors said the man, who was not known for terrorist activities, twice shouted "Allahu Akbar" during the attack, which occurred at around 8:15pm local time (1815 GMT) just outside the city's central pedestrian zone where the soldiers were on patrol.

The case was passed from local to federal prosecutors who typically handle terrorist cases. A spokeswoman for the prosecution service said they were treating the case as one of attempted terrorist murder.

Brussels mayor Philip Close said the alert status, already just one off the maximum level, had not been increased.

"Initial indications are ... that it is an isolated attack, a single person," Close told reporters along a street blocked by police.

Soldiers have routinely patrolled the streets of the Belgian capital amid a heightened security alert since militant shootings and bomb attacks in Paris in 2015 and Brussels in 2016.

In June, troops shot dead a suspected suicide bomber at Brussels' central train station. There were no other casualties. Authorities treated the incident as an attempted terrorist attack. Belgian federal prosecutors said the suspect shouted "Allahu Akbar!" and that they were treating the case as a terrorist incident.

In a separate attack in London, a man with a knife who assaulted two police officers outside Buckingham Palace on Friday night has been arrested, British police said.

The officers suffered minor wounds and did not need to be treated at hospital. The man was arrested on suspicion of grievous bodily harm and assault on police near Queen Elizabeth's London residence.

Britain has been hit this year by four militant attacks in which 36 people were killed, and the country's threat level is at severe, meaning an attack is highly likely.

Footage on Sky News showed emergency vehicles lining the street outside the palace. A Metropolitan Police spokeswoman said she was unable to comment at this stage on the motivation for the incident.

A Reuters witness near the scene said police had cordoned off a wide area around the palace for security.

"The man was stopped this evening, Friday 25 August at approximately 20:35 hours (1935 GMT) by officers at the Mall outside Buckingham Palace in possession of knife," the police said in a statement.

"During the course of detaining him, two male police officers suffered minor injuries to their arm."