Vladikavkaz, Russia ? Chechnya’s acting president escaped an assassination attempt Tuesday when an explosion tore through his motorcade, although one of his bodyguards was killed and three other people were wounded, officials said.

Sergei Abramov, who was appointed to lead the Kremlin-backed Chechen government after the May 9 assassination of Akhmad Kadyrov, was not injured by the roadside blast in the ruined Chechen capital of Grozny.

The attack came six weeks ahead of a scheduled presidential election in Chechnya.

The explosion underscored Russian forces’ inability to purge insurgents from the city, despite a huge troop presence, and challenged Kremlin contentions that Chechnya is stabilizing after nearly five years of war.

Earlier, Chechen officials said 18 members of the presidential security forces and 24 rebels were killed about 20 miles outside Grozny near the village of Avtury, some of the bloodiest fighting in months.

The explosion that hit the convoy was believed to have been a land mine set off by remote control, a method frequently used by separatist rebels to kill and demoralize Russian forces.

One of Abramov’s guards, who was in a car following the president’s, was killed, and three others were wounded, the ITAR-Tass news agency quoted Chechen Prosecutor Vladimir Kravchenko as saying.

Abramov was en route to an inspection of a construction site, ITAR-Tass said. Such inspection trips are an important symbolic component of the Chechen administration’s efforts to portray life as returning to normal in Grozny, much of which is a jagged landscape of war-ruined buildings.

Russia, unable to defeat the rebels and refusing to negotiate with them, has focused on trying to undermine support for the militants with civic improvement projects and by conducting elections in the republic.

But rebels and their supporters have inflicted a series of brazen terrorist acts, including the explosion at a stadium that killed Kadyrov; the 2002 truck-bombing of the Moscow-backed Chechen government’s headquarters, which killed 72 people; and last year’s truck bombing of a military hospital treating soldiers wounded in Chechnya.

In other violence in Chechnya, three soldiers were killed in rebel firing on Russian positions and another was killed by a land mine, an official in the Chechen administration said Tuesday on condition of anonymity.