The move was welcomed by some as a way to strengthen the army, which is facing a growing array of threats from militants inside Lebanon. But it was viewed as provocative by supporters of Hezbollah, the Shiite militant group, who saw it as a bid to reduce the group’s influence over the army. Hezbollah, backed by Iran, supports the Syrian government, while Saudi Arabia is one of the main financiers of the Syrian insurgency.

Speculation arose Monday that the army’s new assertiveness against the Syrian airspace violation was at Saudi Arabia’s bidding in response to the aid package. Security officials said it was policy to respond to any violation of Lebanese territory. The army has also pursued and killed Syrian insurgents on Lebanese territory in recent weeks, according to the official National News Agency.

The Lebanese Army has been hard pressed to control the borders, as militants — both Shiite Hezbollah fighters supporting the Syrian government and Sunni fighters joining the rebels — cross into Syria. There have also been periodic attacks by Syrian warplanes on rebels near the border as well as unsolved car bombings targeting Hezbollah-dominated civilian areas and the Iranian Embassy in Beirut. On Friday, another car bomb killed a former finance minister in downtown Beirut.

The army has also been called upon to calm street battles in the northern city of Tripoli and to attack the mosque complex of an extremist Sunni cleric in Sidon, south of Beirut. The army is seen as unable to confront Hezbollah, which maintains its own powerful independent militia and is believed to wield a strong influence over the army’s many Shiite officers.

In a sign of a worsening humanitarian crisis inside Syria, the United Nations agency for Palestinian refugees, Unrwa, said Monday that 15 Palestinians had died of malnutrition in Yarmouk Camp on the southern border of the capital, Damascus, including five in recent days.