The blast early on Saturday injured at least two people and damaged the Security Ministry, an adjacent military academy, a weather forecasting centre and cars parked outside, Interfax news agency reported.
Georgia's embattled leader, Eduard Shevardnadze, yesterday ordered an investigation into the explosion, which his office linked to a brawl on Friday night between the security chief, Igor Georgadze, and the Defence Minister, Georgi Karakashvili. Mr Shevardnadze had to intervene to separate the two men during a punch- up at Tbilisi airport.
The fracas broke out after a trip to Turkmenistan for a summit meeting of the Commonwealth of Independent States (CIS). Georgia joined the CIS in September in an abortive attempt to secure Russian aid against rebels in the Black Sea region of Abkhazia. On Friday, government troops were reported to have been deployed in the centre of Tbilisi. The Security Minister, Mr Georgadze, accused the military of harassing his staff. The Defence Minister countered by saying that he was the one who had been threatened.
The escalating feud has stirred fears in Tbilisi of a possible putsch against Mr Shevardnadze, who has survived military debacle in Abkhazia and an armed rebellion by supporters of his ousted predecessor, Zviad Gamsakhurdia, but remains highly vulnerable.
The feud between his ministers is said to be rooted in accusations of corruption and a long-running turf battle between rival agencies in a country that has lurched from one catastrophe to another since independence in 1991.
Itar-Tass news agency quote an increasingly frustrated Mr Shevardnadze as saying that 'any sign of confrontation between the Defence Ministry and state security system causes rightful indignation among the people'. The confrontation marks a serious setback for Mr Shevardnadze's efforts to impose order on his fragmenting country. He appointed Mr Karakashvili Defence Minister in July, hoping to break the power of warlords who brought him to power and viewed the country as a feudal fiefdom. Mr Karakashvili has a reputation for honesty, unlike many other members of the government, but his appointment did little to improve Georgia's military fortunes. It was followed by humiliating defeat in Abkhazia.