Fighters linked to the Islamic State group have killed three Libyan security personnel in the country's southwest, the interior ministry said Thursday.

The attack on Wednesday, in the desert some 700 kilometres (430 miles) south of Tripoli, "targeted a patrol of the Umm al-Aranib Martyrs' Brigade, killing three of its members", the ministry said in a statement.

It added that government forces had "killed four members of Daesh (an Arabic term for IS) and destroyed their vehicle".

It said a search was underway for other "terrorists" who had fled.

It said the jihadists were attempting to "undermine stability and terrorise civilians".

IS had on Monday claimed it had attacked the same brigade in the same area a week earlier, killing two members.

The Umm al-Aranib Martyrs' Brigade is largely made up of members of the long-marginalised Tubu ethnic group.

Libya has been roiled by lawlessness since the 2011 fall of despot Moamer Kadhafi, with an array of armed groups vying for control.

IS, encouraged by victories in Syria and Iraq, took advantage of the chaos to seize parts of the country’s north and east, but after a string of offensives saw it kicked out of its final bastion Derna in 2018. 

The group has continued to carry out small-scale attacks.