"All our aspirations, all our actions will be aimed at unifying and consolidating the Chechen people, at reviving our best traditions and customs, at rebuilding the republic's economy and social sphere," Alkhanov said.
Chechen and Russian security forces were on high alert, with officials refusing to disclose the location or time of the swearing-in ceremony until the last minute.
Heavily armed police and security officials lined the streets of the city. Some 500 guests attending the inauguration -- held in a large blue tent inside the government complex -- entered one at a time, passing through a security check and metal detectors.
Authorities were desperate to avoid an attack like the bomb blast that killed Alkhanov's predecessor, Akhmed-hadji Kadyrov, at a public rally in Grozny last May.
Kadyrov's death forced early elections in August. As the Kremlin's hand-picked successor, Alkhanov -- like Kadyrov -- won an easy victory amid complaints of widespread voter fraud.
Alkhanov invoked his slain predecessor during his inaugural speech today.
"Life demands that we develop new approaches to the job entrusted to us," Alkhanov said. "The authorities and the people must be united in their urge to build a peaceful, stable, and safe life in the republic. That was the goal of our first president, Akhmad Hajji Kadyrov, too. There is no other way for us. Only together can we beat our common enemy -- terrorism and banditry."
Alkhanov's election on 29 August came amid a devastating series of terrorist acts, beginning with the near-simultaneous downing of two passenger airplanes and ending with the hostage tragedy in Beslan, North Ossetia.
Chechen militants claimed responsibility for all of the attacks.
More than 430 people were killed over the three-week period, horrifying Russians and putting President Vladimir Putin on the defensive regarding his Chechnya policy.
Putin came to power promising to defeat Chechen militants. But with no end to Russia's five-year military campaign in sight, he has instead been forced to impose a sense of political "normalization" by holding presidential elections and a referendum on a constitution that defines Chechnya as an "inseparable part" of Russia.
ITAR-TASS reported today that Alkhanov, a former police official who served as Kadyrov's interior minister, delivered his oath of office in both the Russian and Chechen languages, with his hand resting on a leather-bound copy of the Chechen Constitution.
One of the first actions Alkhanov will undertake as Chechen president will be to dissolve the current government. But most cabinet officials are expected to be reappointed, including Prime Minister Sergei Abramov and First Deputy Prime Minister Ramzan Kadyrov, the son of Akhmad Kadyrov.
There are doubts about what -- if anything -- Alkhanov can do to bring positive change to the republic.
In the run-up to the election, Alkhanov pledged to revive the republic's economy and tackle the country's staggering 70-percent unemployment rate.
He also vowed to fight violence and lawlessness in the republic, and has indicated he may hold talks with former Chechen President Aslan Maskhadov if Maskhadov publicly renounces his separatist goals.