Egyptian police in Sinai have surrounded 10 Lebanese men wanted on suspicion of plotting attacks against Egypt, a security source said on Sunday.
The men are part of a group sought by Cairo for their links to Lebanon's Hezbollah, the source said.
Tensions between Egypt, a predominantly Sunni country, and Hezbollah, a Shiite group backed by Iran, have been running high since Hezbollah leader Hassan Nasrallah in December accused Cairo of complicity with Israel in its siege of Gaza.
Cairo said on Wednesday it had detained 49 Egyptian, Palestinian and Lebanese men linked to Hezbollah, accusing them of planning attacks in Egypt.
On Sunday a prosecution source said five Egyptians and one Palestinian had been charged with spying and possessing firearms without a licence.
Nasrallah said in response that one of those held was a Hezbollah member and that he and up to 10 others were trying to supply military equipment to the Hamas-run Gaza Strip. He denied they had plans for attacks inside Egypt.
The six men admitted having links with Hezbollah but denied other charges, according to the prosecution source.
A separate prosecution source said at least one Sudanese national was among the detained, and that police had found explosives and bomb-making material in their possession.
Egypt press slams Nasrallah
The Egyptian press on Sunday slammed Hezbollah leader Hassan Nasrallah as a war criminal who should be put on trial after he admitted that his militants in Cairo were helping Hamas in the Gaza Strip.
Nasrallah said on Friday that a man Cairo is holding on suspicion of planning attacks is a member of his group and was providing logistical help to Hamas, but denied seeking to destabilize Egypt.
"A criminal who knows no mercy" cried the blood-red headline in the state-owned al-Gomhuria which reserved the whole of its front page for an editorial bashing Nasrallah, repeatedly referring to him as "Sheikh Monkey."
"Sheikh Monkey, we will not allow you to belittle our judicial symbols, for you are a highway robber, a pure criminal who has killed his own people but we will not allow you to threaten the peace and security of Egypt," editor Mohammed Ali Ibrahim wrote.
Al-Ahram newspaper, which is also state-owned, said Nasrallah’s admission that Hezbollah is operating in Egypt provided grounds for prosecution.
"The admission by (Nasrallah) of sending agents into Egypt... puts him at the forefront of accusations and requires dealing with him under Egyptian law, or international law and issuing an (Interpol) red notice for his arrest," said editorial writer Ahmed Mussa.
"Egypt must start proceedings to try him in an international court. He has admitted to the crime. He must be handed to the Lebanese government as a war criminal," Karam Gabr, editor of the pro-regime Rose al-Yussef, told Egyptian television.
Helping the Palestinians
In his speech on Friday, Nasrallah confirmed that Sami Shihab, a Lebanese citizen among the detained, was a member of Hezbollah and was working to help Hamas against Israel.
"If helping the Palestinians is a crime, I officially admit to my crime."
Hezbollah, which is backed by Egypt's regional rivals Iran and Syria, is a vocal supporter of Hamas, the Islamist rulers of Gaza, and has lashed out at Egypt for closing its border crossing with the Palestinian enclave.
An Israeli cabinet minister said on Sunday that Nasrallah deserved to die.
"Nasrallah deserves death and I hope that those who know what to do with him will act and give him what he deserves," said Transport Minister Yisrael Katz.
Israel and Hezbollah fought a devastating war in Lebanon in 2006 which ended with Israel failing to achieve any of its aims.