World News Update, what you need to know

A senior Hamas leader says it carried out the kidnapping and killing of three Israeli teens in the West Bank in June - the first time anyone from the Islamic militant group has admitted it was behind the attack that helped spark the current Gaza war.

ELSEWHERE:

WASHINGTON, Aug 21 AFP - Journalist James Foley's jihadist captors have demanded a ransom of 100 million euros ($A150 million) for his release, says his employer GlobalPost.

CAIRO, Aug 21 AFP - Jailed Australian journalist Peter Greste and two other Al-Jazeera journalists jailed by Egypt for alleged ties with Islamists have filed appeals against their convictions.

DUBLIN, Aug 21 AFP - Irish authorities are testing a "suspected case of Ebola virus" after a person who travelled to an affected area in Africa was found dead, health authorities say.

WASHINGTON, Aug 21 AFP - Two American missionaries who fell ill with the dangerous Ebola virus while working in Liberia have been released from a US hospital.

WASHINGTON, Aug 21 AFP - The United States is looking to keep pressure on jihadist militants in Iraq, launching air strikes after the murder of a journalist underlined the international threat.