Europe urges release of kidnapped Libyan lawmaker
In a statement, the missions said they "express their deep concern regarding the continued disappearance" of Sergewa "and call for her immediate release".
"We continue to call on relevant Libyan authorities to conduct urgent investigations into her disappearance, and provide an update on her whereabouts," it added.
The statement was signed by the EU's delegation and the embassies of Austria, Belgium, Bulgaria, Finland, France, Germany, Italy, Holland, Portugal, Spain, Sweden and the UK.
The raid that resulted in the kidnapping of Sergiwa also reportedly saw her husband shot in the leg.
A family member told Amnesty International how the lights cut out in the whole area before the raid.
"They came inside the house and told us to get down. They shot dad in the leg and beat him. I tried to stop them and they hit me, too," they said.
An eyewitness said the militiamen spoke with a Benghazi accent and were driving cars with "military police" written on them. After the raid, the words Awliya al-Dam, the name of a militia affiliated with the LNA, were found graffitied on a wall inside the house.
The raid on Sergiwa's house came shortly after she spoke on Al-Hadath television, an outlet that backs Haftar.
During the broadcast she had called for "an end to the bloodshed", referring to an offensive launched in April by Haftar's forces to wrest control of the capital Tripoli from rival fighters loyal to the UN-recognised Government of National Accord.
"The trend of attacks against politicians, political activists and members of civil society, and in particular women, is unacceptable," the statement said.
On 17 October, the UN mission in Libya urged authorities in the country's east to reveal Sergiwa's fate.
Read more: Who is Khalifa Haftar, Libya's CIA-linked rogue general-turned-warlord?
The UN also said that since the start of Haftar's offensive, it had recorded an "alarming increase" in enforced disappearances across Libya.
Sergiwa's case is the latest in a string of Libyan women targeted with attempted killings, abduction, physical and sexual assault and harassment, and intimidation campaigns since 2014.