A prominent Libyan human rights lawyer and activist has been assassinated in her home in Benghazi.

Armed men fought their way into the house of Salwa Bughaighis before shooting her.

Ms Bughaighis, a former parliamentarian, was an outspoken critic of many of the armed groups, which still control much of Libya.

Her husband Issa was present at the time of the attack and has since gone missing.

The killing is the latest in a string of attacks on politicians, activists and journalists who have spoken out against the actions of certain armed groups.

Ms Bughaighis was killed hours after she had cast her vote in Libya's parliamentary elections.

A medical source at a Benghazi hospital confirmed she died of a gunshot wound to the head.

She had also been a strong critic of Muammar Gaddafi and had joined some of the first protests against him in 2011.

She later became a member of Libya's National Transitional Council which governed the country during and directly after the uprising. She leaves behind three sons.

The US Ambassador to Libya Deborah Jones said the killing was "heartbreaking".

She described the killing as a "cowardly, despicable, shameful act against a courageous woman and true Libyan patriot."

Earlier this week a candidate standing in parliamentary elections in the southern city of Sabha was assassinated, local media reported.

Libya has suffered from instability and violence since the downfall of Gaddafi in 2011.

The government has struggled to disarm the various armed groups that remained from the war.