Israeli warplanes have flown over Lebanon's Bekaa valley and the north of the country but did not launch an attack, according to a security source in the area.
The source said that the Israeli jets and drones had come under anti-aircraft fire but had not been hit and had not opened fire themselves.
An Israeli army spokesman said no attack had taken place: "We haven't attacked in Lebanon since the start of the ceasefire."
Military jets, helicopters and drones had circled over the area, 60km (35 miles) east of Beirut, according to a Reuters reporter.
Dan Gillerman, Israel's ambassador to the UN, said on Friday that Israel objects to the inclusion of countries that do not have diplomatic ties with the Jewish state in a planned UN force for southern Lebanon.
He said: "It would be very difficult if not inconceivable for Israel to accept troops from countries who do not recognise Israel, who have no diplomatic relations with Israel."
Gillerman said Israel would be "very happy" to accept troops from Muslim countries it has friendly relations with.
He said: "But to expect countries who don't even recognise Israel to guard Israel's safety I think would be a bit naive."
Malaysia and Indonesia have each offered to send 1,000 troops to Lebanon. Both countries, with Muslim majority populations, have no diplomatic ties with Israel and strongly support the Palestinian cause.
Syed Hamid Albar,
Malaysia's foreign minister, dismissed Gillerman's remarks. He said: "We're going to be on Lebanese territory...we're not going to be on Israeli territory."
"As a matter of good form in peacekeeping, you want a force which is broadly acceptable in its composition to both sides"
Malloch Brown, UN deputy secretary-general
Mark Malloch Brown, the UN deputy secretary-general, said "the final word" on troop deployment was up to the UN.
Malloch Brown said he had discussed the issue with Tzipi Livni, the Israeli foreign minister on her visit to UN headquarters on Wednesday.
He said: "I think they are reflecting on it."
Objections from Israel could complicate efforts by the UN to quickly assemble a force for southern Lebanon to enforce a ceasefire between Hezbollah and Israel that took effect on Monday after more than a month of fighting.
Malloch Brown said: "As a matter of good form in peacekeeping, you want a force which is broadly acceptable in its composition to both sides."
A UN security council resolution calls for the deployment of up to 15,000 troops, including a 2,000-strong UN force which has been in Lebanon since 1978. But a senior UN official said that he doubted enough countries would come forward to reach that goal any time soon.