Two car bombs exploded in the Libyan capital, Tripoli, killing two people and injuring several others early on Sunday, a security official said.

The first bomb went off in a main street near a military college used as a base for former rebel forces, killing two and wounding four people, according to the official who spoke on condition of anonymity because he wasn't authorized to speak to the media.

Thirty minutes later, a cab parked in a narrow alley by the Interior Ministry exploded, wounding several people. The official said a third car bomb was discovered, also near the ministry, but was defused.

The bombings came on the eve of Libya's first anniversary of the fall of Tripoli. On Aug. 20, 2011, rebel fighters behind the eight-month uprising to topple Moammar Gadhafi's regime liberated the city.

Gadhafi was captured and killed last October but many Libyans are convinced that some of his associates remain at large around the country.

After Sunday's blasts, officials blamed Gadhafi's loyalists, saying they were plotting attacks and seeking to spread fear among the public and prevent the country from returning to normalcy.

"I hold former regime aides fully responsible for this cowardly action," said deputy interior minister, Omar al-Khadrawi, as he visited one of the sites of the blasts. He said "the same kind of bombs and the same tactics and equipment" were used in previously foiled car bombing attacks in Tripoli.

The city security authorities went on high alert after the bombings, which came just hours before Muslim prayers are to take place at the main Tripoli square for the Eid al-Fitr holiday that marks the end of the month of Ramadan.

Low-level attacks have been on the rise in both Benghazi, to the east, in Misrata, in central Libya, and in the capital, Tripoli.

Last month, Libya elected its first parliament after the nation's first-ever free vote. The house elected a president earlier this month and is now trying to form a new government. The future cabinet faces a mountain of challenges, including the need to form a strong national army under which various militia groups would unite and follow one central command.