Egypt is under pressure to halt smuggling from the Sinai
Egyptian security forces are scouring the Sinai Peninsula for 13 alleged Hezbollah operatives, officials say.
The men were named during the interrogation of 49 Hezbollah suspects that Egypt said it was holding last week, unnamed security officials said.
Hezbollah leader Hassan Nasrallah has confirmed one of the 49 is a member of the Lebanese movement but denied claims it was planning attacks in Egypt.
Last week, Israel warned of likely attacks on Israelis visiting the area.
On Monday, an Israeli tourist was stabbed by a Libyan worker in the Sinai resort of Nuweiba.
But reports suggested the incident was an attempted burglary or a financial dispute, rather than a politically motivated attack.
The Sinai's beach resorts have long been popular with Israelis, although warnings of attacks have reduced visitor numbers in recent years.
Egypt has accused the 49 suspects - reported to include Lebanese, Syrians, Palestinians, Sudanese and Egyptians - of being agents for Hezbollah and planning "hostile operations" in Egypt.
Hassan Nasrallah said Egypt was trying to turn its people against Hezbollah
On Sunday, Egypt's attorney general added espionage to the list of charges the 49 suspects face.
Egyptian prosecutors say Hezbollah told the 49 men men to collect intelligence from villages along the Egypt-Gaza border, tourist sites and the Suez Canal.
The Hezbollah leader Hassan Nasrallah has confirmed that one of them, Sami Shihab, is a member of the organisation.
But he said Mr Shihab had been trying to get military equipment into Gaza, denying that the group was planning attacks in Egypt.
Hezbollah supports Hamas, the Islamic movement which controls Gaza.
It has strongly criticised Egypt for failing to open its border with Gaza to relieve the Israeli-led blockade.
In December, as Israel carried out an offensive in Gaza - with the stated aim of ending Hamas rocket fire into Israel - Mr Nasrallah called on Egyptians to protest and force their government to open the border.
Egypt has been under pressure from Israel to curb weapons smuggling through tunnels from the Sinai peninsula under the border with Gaza.
Hezbollah is both a political faction, with seats in the Lebanese government, and a military organisation which fought a war against Israel in 2006.