TRIPOLI, May 5 (Xinhua) -- The Libyan Interior Ministry on Saturday completed preparation of a joint security and military plan to secure the capital Tripoli, a few days after the deadly Islamic State (IS) suicide attack on the Libyan Higher Commission of Elections.

According to a statement issued by the ministry, the announcement of the plan came after a broad meeting of senior military and security officials, including Libyan interior minister and the military chief of staff.

The meeting also focused on the security arrangements, mainly a unified security plan between all the military and security services aimed at securing the city of Tripoli and its outskirts, the statement said.

IS suicide bombers on Wednesday attacked the headquarters of Libyan Higher Commission of Elections in Tripoli, killing 15 people and injuring 21 others.

IS claimed responsibility for the suicide attack, when the organization's media arm, A'maq, tweeted a statement saying the attack had been carried out based on orders of the organization's spokesman, Abu Hassan al-Muhajir.

The attack took place as the UN-backed government, in cooperation with the UN Support Mission in Libya, prepares to hold presidential and parliamentary elections before the end of this year, as proposed by the head of the mission, Ghassan Salame in September 2017.

Libya has remained mired in chaos following the 2011 uprising that toppled former leader Muammar Gaddafi. It is struggling to make a democratic transition amid political division and unrest, as well as dominance of armed groups and militias with shifting loyalties.