Islamist militant organisation Ansar Bayt al-Maqdis has threatened to attack any tourists who do not leave Egypt, setting a 20 February deadline for foreigners to depart "before it's too late".
"We recommend tourists get out safely before the expiry of the deadline," read the statement published on the group's Twitter account.
The group, which mainly operates in the Sinai Peninsula, claimed responsibility for the bombing of a tourist bus near a border crossing with Israel, on 16 February, that killed three South Koreans and an Egyptian and wounded 13 more.
In a Twitter statement, Ansar Bayt al-Maqdis stated that one of its members was responsible for the deadly explosion.
"Ansar Bayt al-Maqdis has successfully sacrificed one of its heroes to detonate the bus headed toward the Zionists, and this comes as part of our economic war against this [Egyptian] regime of traitors.
"With God's will we will be watching this treacherous gang of infiltrators and we will target their economic interests in all places in order to paralyse their hands from [hurting] Muslims," the statement said.
Since the army's removal of Mohammad Morsi from power in July, Islamic militancy has escalated in the Sinai region, leading to a wide-scale crackdown on militants by Egyptian security forces.
The Sinai suicide bomb was the first in almost a decade to target tourists as violence continues to damage Egypt's faltering tourism industry.
Until now, Islamists have predominantly targeted military and government representatives, killing hundreds of policemen and soldiers since Morsi's overthrow. The group also claimed responsibility for the rocket attack last month that downed a military helicopter and killed five Egyptian soldiers.
This warning for tourists demonstrates a tactical move away from state targets towards soft targets.
It marks a new development in Ansar Bayt al-Maqdis' campaign to overthrow the interim government headed by army chief Field Marshal Abdel Fattah al-Sisi.