The final stage of Arutyunian's capture was broadcast live on Georgia's main television channels.
Addressing reporters during an impromptu news briefing, Interior Minister Ivane Merabishvili said Arutyunian was apprehended in the Vashlijvari suburb of the Georgian capital Tbilisi.
Arutyunian resisted arrest, opening fire on police officers. Merabishvili said the head of the Interior Ministry's counterintelligence department, Zurab Kvlividze, was killed in the shootout.
"As [police] went to the house of the suspect, Vladimir Vladimirovich Arutyunian, he opened fire, causing the death of one of our men, Zurab Kvlividze," Merabishvile said. "Arutyunian was wounded in the shootout that followed and, a few minutes later, detained by a special police unit."
Arutyunian sustained wounds in the leg and chest and was rushed to Tbilisi's Republican Hospital for treatment, where his condition is reportedly not life-threatening.
Merabishvili insisted Arutyunian was still considered a suspect and that police would need a few more hours, perhaps days, to determine whether he is the man who allegedly threw the grenade.
Attack On Two Presidents
The incident was not reported until U.S. President George W. Bush left Georgia after addressing tens of thousands of people on Tbilisi's Freedom Square on 10 May.
Georgian authorities reported then to the U.S. Secret Service that someone in the crowd had thrown a hand grenade folded in a red handkerchief toward the stage where Bush and Georgian President Mikheil Saakashvili were standing.
Officials said the Russian-made grenade landed within 30 meters of both leaders, but failed to go off due to an apparent malfunction. A Georgian security officer reportedly picked up the device and removed it from the area.
Georgian police have since been engaged in a nationwide manhunt that also involved U.S. investigators.
Georgia's Interior Minister initially offered a reward worth 20,000 laris ($11,000) to anyone with information leading to the arrest of a suspect. That reward was raised to 150,000 laris three days ago.
Georgian television channels today showed photographs of a dark-haired man that were taken while he was attending Bush's address. Police said the man shown in the pictures is Arutyunian, an unemployed ethnic Armenian who lives alone with his mother.
Arutyunian's mother, Anzhela, who was briefly detained for questioning, told reporters her son had disappeared for the past three days before returning home overnight.
"He hasn't been home for the past three days," she said. "Before that, he was always here."
U.S. Involvement In Hunt
The U.S. Secret Service today said it was monitoring the investigation conducted by the Georgian authorities. It also denied being involved in Arutyunian's arrest.
Georgia's Imedi television, however, said today that FBI agents were searching Arutyunian's apartment for further evidence.
Unconfirmed Georgian news reports quote Interior Ministry officials as saying explosives and detonators, as well as chemical substances that could possibly serve to make a bomb, were found at Arutyunian's home.
The Georgian presidential administration said today that, following the news of Arutyunian's arrest, Saakashvili has decided to cut short his vacation in the Netherlands and return to Tbilisi.
(based on Imedi TV and local news reports)