Thirty Egyptian tribes based in Sinai said on Sunday they would confront militant groups including an Islamic State affiliate that has killed hundreds of soldiers and police, in a boost to Egypt's efforts to improve security.
The Sinai Tribal Federation said it had held its first meeting on Sunday to discuss ways to tackle militants seeking to topple the Cairo government.
The tribes would work "in coordination with the relevant agencies and institutions of the formal state ... to support the state and the armed forces in their war against terrorism," the alliance said in a statement.
An insurgency based in the Sinai Peninsula has intensified since 2013 when Islamist president Mohamed Morsi was ousted following mass protests against his rule.
The Federation agreed to form two groups of youth volunteers, one of which would help security forces gather information on suspected militants or their supporters and monitor routes used to smuggle weapons.
The second would participate in the military campaign alongside armed forces, the statement said.
Last month, Egypt extended by three months a state of emergency imposed on Northern Sinai in October after Islamist militants stepped up attacks in the thinly populated but strategic peninsula bordering Israel, Gaza and the Suez Canal.