The Lebanese army tightened security around the Palestinian refugee camp of Ain el-Hilweh on Saturday less than 24 hours after the arrest of a cell led by an Egyptian national hiding in the shantytown that lies near the city of Sidon. The state-run National News Agency said that all incoming and outgoing vehicles were being subject to strict searches, and drivers’ identity cards and papers were checked. It added that the additional checks were causing significant traffic at the camp’s entrances. The tighter measures came only hours after the army’s general command said that the military intelligence arrested 19 people in connection with an ISIS-linked network that is led by Egyptian citizen Fadi Ibrahim Ahmed, also known as Abou Khatab, who is hiding inside Ain el-Hilweh. An army communique said that the network was suspected of planning a terrorist attack. By longstanding convention, the Lebanese army does not enter Palestinian refugee camps in Lebanon, leaving the factions themselves to handle security. Ain el-Hilweh -- the most densely populated Palestinian camp in Lebanon -- is home to some 61,000 Palestinians, including 6,000 who have fled the war in neighboring Syria. Several armed factions including extremist groups have a foothold in the camp which has been plagued for years by intermittent clashes. The arrests of the 19 suspects on Friday came after several embassies warned of a heightened threat of terrorism. The US mission said that “due to ongoing threats to locations such as the Casino Du Liban in Jounieh, Lebanon, the US Embassy in Beirut has barred any movement of US government staff to that Casino.” The French ministry of foreign affairs advised its citizens in Lebanon to be vigilant over the coming 48 hours due to an elevated risk of attacks in public areas in the country.  The UK Foreign Office also put out an updated travel warning.