Two people have been killed in a grenade attack near a courthouse in Liege, Belgium.

An unconfirmed number of attackers threw at least four grenades during the attack at around noon on Tuesday in Saint-Lambert Square, near a busy Christmas market.

It is thought that the attack, which has left a two-year-old critically injured, was carried out using 'thunderflash' explosive devices. Witnesses have reported that the attackers also fired shots from Kalashnikov rifles.

One of the assailants is believed to have died during the attack, while a second was arrested. A third is thought to be still at large according to reports from Belgian paper Le Soir.

Witnesses reported hearing shots up to an hour after the attack, with television footage showing blood splashed across the square's cobblestones.

An image has appeared on Twitter appearing to show suspects being arrested, but its validity is not confirmed.

Grenade attack
An unconfirmed image released on twitter appears to show a suspect being arrested