Lebanese anti-aircraft guns fired at Israeli warplanes over southern Lebanon on Wednesday, a military spokesman said, indicating that Lebanon's army is taking a new assertiveness toward Israel.

The Israeli planes had "violated Lebanese sovereignty, posing a challenge to United Nations Resolution 1701," the spokesman said, referring to the Security Council resolution that ended Israel's 34-day war with Hezbollah guerrillas in Lebanon last August.

The official spoke on condition of anonymity as is customary for the Lebanese military in the absence of a formal statement.

In Jerusalem, the Israeli military declined to comment on the Lebanese statement.

The Lebanese guns did not appear to have hit any Israeli planes, but the incident was the first time that the Lebanese military had fired at Israeli aircraft since the war.

Israeli warplanes have flown reconnaissance missions over Lebanon for years, despite protests from the Beirut government.

Israel, which often declines to comment on the operations of its air force, has defended the over-flights since the war as necessary to check that Hezbollah is not being re-armed in violation of the ceasefire.

On Feb. 7, Lebanese troops fired at an Israeli military bulldozer after it allegedly crossed into south Lebanon. The Israeli army fired back, but later said the bulldozer was still on the Israeli side of the UN-demarcated border.

After the war, the Lebanese army deployed about 16,000 troops in southern Lebanon, where Hezbollah guerrillas had previously been in control. The United Nations has sent more than 12,000 peacekeepers to the area to monitor the ceasefire.