A bomb exploded outside the Moroccan embassy in Libya's capital, a security official said Monday, just hours after a gun attack on the building housing South Korea's mission to the country.

"A bomb inside a bag went off near the gate of the Moroccan embassy in Bin Ashour area" in central Tripoli, the official said, adding "there were no casualties".

There was visible damage to a "few cars in the area", he said.

"The sound of the explosion was very strong, and the house was shaking for few seconds," an unnamed witness told AFP.

The Moroccan embassy is not currently active, and it was unclear if anyone was inside the building at the time.

Morocco is currently hosting a UN-backed dialogue between representatives of the two rival governments controlling the country, with talks to resume on an unspecified date.

The bombing came hours after gunmen opened fire on South Korea's embassy compound from a passing car on Sunday, killing two Libyan guards and wounding a third person.

The Islamic State jihadist group claimed responsibility for the South Korean attack on Twitter, according to SITE Intelligence Group.

Libya has been plagued by chaos since the end of the 2011 revolt that toppled Moamer Kadhafi, with heavily armed militias battling for control of its cities and oil wealth and rival governments and parliaments vying for power.

The country has had two governments and parliaments since Tripoli was seized in August by the Islamist-backed Fajr Libya militia and the internationally recognised government fled to the country's far east.