GROZNY, Russia — Suicide bombers on bicycles detonated explosives in Chechnya on Friday, killing at least four police officers and a civilian in coordinated attacks in the capital, officials said. The suicide bombers approached police officers in two central locations in Grozny and blew themselves up, killing two officers in each attack, said Chechnya's Interior Minister Ruslan Alkhanov in televised remarks. Russian emergency services spokesman Alexei Zemskov said three other people were wounded.