DAMASCUS, Syria — Israel carried out a wave of heavy airstrikes across Syria as its troops advanced deeper into the country, a Syrian opposition war monitor said Tuesday. Israel denied its forces were advancing toward Damascus after they pushed into a buffer zone inside Syria following the overthrow of President Bashar Assad.

Associated Press reporters in the capital heard heavy airstrikes overnight and into Tuesday on the city and its suburbs. Photographs circulating online showed destroyed missile launchers, helicopters and warplanes.

There was no immediate comment from the insurgent groups — led by Hayat Tahrir al-Sham, or HTS – that have taken control of much of the country. Their lightning advance brought an end to the Assad family's half-century rule after nearly 14 years of civil war. There are concerns over what comes next.

'Damascus is more beautiful now'

Life in the capital is slowly returning to normal after the overthrow of Assad, who fled the country over the weekend and has been granted political asylum in Russia.

Private banks reopened on instructions from the Central Bank, said Sadi Ahmad, who runs a branch in the upscale Abu Rummaneh neighborhood. He said all his employees returned to work.

Shops also reopened in the city's ancient Hamidiyeh market, where armed men and civilians could be seen buying things like perfume and ice cream. A clothing shop owner, who asked not to be named for fear of retribution, said he hoped vendors would no longer have to pay bribes to security officials.

At Bakdash, a famous ice cream shop, a poster outside read: "Welcome to the rebels of free Syria. Long live free Syria."

"Damascus is more beautiful now," said Maysoun Qurabi, who was shopping in the market. "It has a soul, and people feel at ease and secure." Under Assad, she said, "people were hungry and scared. The regime was strong."

Israeli incursion draws condemnation

In the immediate aftermath of Assad's fall, Israeli forces moved into a roughly 400-square-kilometer (155-square-mile) buffer zone inside Syria that had been established after the 1973 Mideast war, a move it said was taken to prevent attacks on its citizens.

Israel has also said it is striking suspected chemical weapons sites and heavy weapons to prevent them from falling into the hands of extremists. Israeli officials rarely acknowledge individual strikes.

Israel has a long history of seizing territory during wars with its neighbors and occupying it indefinitely, citing security concerns. Israel captured the Golan Heights from Syria in the 1967 Mideast war and annexed it in a move not recognized internationally, except by the United States.

The Britain-based Syrian Observatory for Human Rights, which has closely tracked the conflict since the civil war erupted in 2011, said Israel has carried out more than 300 airstrikes across the country since the rebels overthrew Assad.

The Observatory, and Beirut-based Mayadeen TV, which has reporters in Syria, said Israeli troops are advancing up the Syrian side of the border with Lebanon and had come within 25 kilometers (15 miles) of Damascus, which the Israeli military denied.

Israel denies advancing toward Damascus

Lt. Col. Nadav Shoshani, an Israeli military spokesperson, said "the reports circulating in the media about the alleged advancement of Israeli tanks towards Damascus are false." He said Israeli troops are stationed within the buffer zone in order to protect Israel.

Israel's military had previously said troops would enter the buffer zone "and several other places necessary for its defense."

Israeli media meanwhile reported that the air force was methodically destroying Syria's military assets to ensure whoever rules the country next would have to rebuild them.

The operations "have been systematically destroying all that remains of the escaped tyrant's military," wrote Yossi Yehoshua, the military correspondent for Israel's largest daily, Yediot Ahronot.

"Dozens upon dozens of targets, including arms depots of various kinds, have been hit in waves of attacks so as to prevent them from falling into hostile hands and from posing a threat to Israel." The air force "currently enjoys complete freedom of action," he added.

Egypt, Jordan and Saudi Arabia have condemned Israel's incursion, accusing it of exploiting the disarray in Syria and violating international law.

Turkey, which has been a main backer of the Syrian opposition to Assad, also condemned Israel's advance. The Turkish Foreign Ministry accused Israel of"displaying a mentality of an occupier" at a time when the possibility of peace and stability had emerged in Syria.

U.N. spokesman Stephane Dujarric on Monday said Israel's incursion constitutes a violation of the 1974 disengagement agreement and called on both Israel and Syria to uphold it.