GROZNY, Russia - A suicide bomber blew himself up in the capital of Russia's restive Chechnya on Wednesday, outside a theatre where the region's Kremlin-appointed president was waiting for a concert to begin, officials said.

Chechen President Ramzan Kadyrov, a former separatist rebel who switched sides to support Russia, was not injured. But the Investigative Commission, Russia's top investigative body, said five police officers and two civilians were wounded in the blast.

The explosion, at about 6 p.m., shook the centre of Grozny, a city gingerly trying to come back to life after being devastated in two wars between separatists and Russian forces since 1994.

Kadyrov's office said in a statement that police guarding the theatre noticed a man behaving suspiciously and that when they shouted at him, he detonated an explosive device.

Major offensives in Chechnya died down in the early part of the 1990s, but scattered small clashes and bombings continue to plague the region. A rebel Chechen leader claimed responsibility for the March subway suicide bombings in Moscow that killed 40 people.

Violence seen as inspired by the Chechen insurgency has also gripped the neighbouring regions of Dagestan and Ingushetia.

Kadyrov's father also was a Kremlin-backed president of Chechnya, but he was assassinated in a bomb attack in 2004.

Human rights activists allege the younger Kadyrov has directed widespread human rights violations, including abductions and summary executions of suspected rebels and sympathizers.