UPDATE 3-Car bombs kill two in Libyan capital

* Three car bombs explode near interior, security facilities

* First lethal car bomb since Gaddafi's fall kills two

* Violence remains problem for new leadership

TRIPOLI, Aug 19 (Reuters) - At least two people were killed

when three car bombs exploded near interior ministry and

security buildings in the Libyan capital on Sunday, the first

lethal attack of its kind since Muammar Gaddafi's fall last

year, security sources said.

There was no immediate claim of responsibility for the

blasts, the latest examples of the violence that has remained a

problem in Libya despite the peaceful transfer of power to the

new government after elections in July, the first in decades.

Gaddafi's overthrow and death, after 42 years of eccentric

personal rule, left a power vacuum that was filled by local

militias and other armed groups that security forces have

struggled to subdue, and sporadic shootings and explosions.

Ambulances and firefighters rushed to the scenes of Sunday's

blasts, in residential areas in central Tripoli, and large

numbers of police were deployed to cordon off the sites and

remove the charred vehicles and other debris.

The first bomb blew up near the interior ministry's

administrative offices in Tripoli but caused no casualties, the

sources said. On arriving at the site, police found another car

bomb that had not blown up.

Minutes later, two car bombs exploded near the former

headquarters of a women's police academy, which the defence

ministry has been using for interrogations and detentions, the

sources said, k il ling two civilians and wounding three.

The blasts, which caused minor damage to the two buildings

and shattered windows of nearby cars and buildings, took place

early in the day as worshippers prepared for mass morning

prayers marking Eid al-Fitr, the Muslim celebration that marks

the end of the fasting month Ramadan.

"The (victims) were two young men in their 20s. They drove

past the police academy precisely at the time of the explosion,"

a security source said.

Security sources said they had no immediate clues to who had

planted the bombs and had received no claims of responsibility.

A surge of violence during Ramadan included a car bomb in

Tripoli near the offices of the military police and an explosion

at the empty former military intelligence offices in the eastern

city of Benghazi, the cradle of the revolt against Gaddafi.

The latest attacks will test the mettle of the national

assembly, which made improving security a priority when it took

power earlier this month from the National Transitional Council

of opposition forces that toppled Gaddafi.

Its main task will be imposing its authority on numerous

armed groups, mostly militias who took part in the uprising, who

refuse to lay down their weapons. Disarming them remains a

challenge.

The 200-member assembly will name a new prime minister who

will pick his government, pass laws and steer Libya to full

parliamentary elections after a new constitution is drafted next

year.

The persistent violence has affected Libya's relations with

other countries and international organizations whose help it

needs in its drive for stability, security and economic

reconstruction.

The International Committee of the Red Cross announced that

it was suspending its activities in Benghazi, Libya's second

biggest city, and Misrata after one of its compounds in Misrata

was attacked with grenades and rockets.

The fate of seven Iranian relief workers, official guests

of the Libyan Red Crescent Association, remains unknown almost

three weeks after they were kidnapped by gunmen in the heart of

Benghazi.