Four soldiers were killed and three people injured in an apparent suicide bombing in Chechnya on Monday, dpa cited Russia's RIA Novosti news agency as reporting. The bombing took place at a roadside checkpoint in the capital Grozny. A man who is thought to have detonated the bomb died, the Interfax news agency reported. Earlier in neighbouring Dagestan, two Russian anti-terrorism police officers were killed and a third injured when unknown assailants opened fire on their vehicle, RIA Novosti reported.