Libya's internationally recognised parliament on Monday suspended its participation in UN-brokered talks on the future of the war-wracked North African state, officials said.
"The chamber of representatives today voted in favour of suspending its participation in the dialogue," MP Issa al-Aribi announced on Facebook, ahead of a new round due to open in Morocco on Thursday.
He did not elaborate, but both the LANA state news agency and parliament's own Facebook page confirmed the suspension.
The parliament said it would issue a statement later giving the reasons for the decision which came "after last Friday's terrorist attacks in Al-Qoba which killed or wounded dozens of people".
The Islamic State jihadist group said it was behind suicide car bombings that the health ministry said killed 40 people, including six Egyptians, in the eastern town.
Another parliamentarian, speaking on condition of anonymity, said the decision to pull out of talks was taken over fears that the international community would exert pressure to include Islamists in a future unity government.
Last week's beheading of 21 mainly Egyptian Coptic Christians by IS sparked Cairo to launch air strikes against the jihadists in Libya and call for an international coalition to hit the jihadists.
State media in Egypt said almost 15,000 of its nationals have since flocked home from Libya via the border crossing at Sallum.
UN envoy Bernardino Leon told the Security Council last week that the only cure for Libya's trauma was political.
The United States on Monday renewed its call for dialogue, warning of the high stakes at play.
"We reiterate our call for all Libyan stakeholders to participate in the UN-led political dialogue," State Department spokeswoman Jen Psaki told reporters in Washington.
- Daunting task -
Signup to our newsletter and follow us on Facebook and Twitter!
"Those who choose not to participate are excluding themselves from discussions which are critical to combating terrorism as well as to the overall peace, security and the stability and security of Libya."
The international community faces a daunting task to find a political solution to the lawless nation's political and military crisis.
Libya is awash with weapons and opposing militias are battling for control of its cities and oil wealth.
It has two rival governments and parliaments, those recognised by the international community sitting in the far east of the country and the others with ties to Islamists in the capital, Tripoli.
Since launching efforts at dialogue in September, Leon has been unable to bring together leading players from the rival camps.
The United Nations had invited the elected parliament and its Tripoli rival, the Islamist-dominated General National Congress, to the new round of talks in Morocco.
On February 11, Leon met separately with officials from both sides in the southern Libyan oasis town of Ghadames -- the first between the two bodies since a national dialogue was launched last September.
The UN envoy called the indirect talks "positive and constructive", despite not managing to sit the rivals round the same table.
Analysts believe efforts to bridge the gap will fail so long as the rival armed factions -- led by General Khalifa Haftar for the elected government and Fajr Libya for the GNC -- do not talk face to face.
The situation has been further complicated by the factions each having their own regional backers.
Egypt, the United Arab Emirates and Saudi Arabia are said to support Haftar, while Qatar and Turkey favour Fajr Libya.
Libya plunged into chaos after the 2011 revolution that toppled and killed Moamer Kadhafi, with heavily armed rival militias that had fought the longtime dictator's forces rising to prominence.