As the Voice of Israel today announced new Israeli and Palestinian casualties in actions in the Bekaa Valley, and Israeli officials warned Syria against further cease-fire violations in eastern Lebanon, there were increasing reports of extensive Israeli and Syrian troop movements in anticipation of fresh fighting for control of the area.

Front-page reports yesterday and today in the independent daily L'Orient-Le Jour cited troop movements around Syrian and Israeli lines on the rim and on the floor of the valley.

Israeli Army spokesman Col. Yehiel Ben Zvi would neither confirm nor deny the reports. "It is true there have been numerous cease-fire violations," he added.

L'Orient-Le Jour reported that hundreds of Israeli tanks and armored cars have descended the Lebanon Mountain heights on the west wall of the valley down to the valley's floor since Friday. Saturday's paper carried a telephoto picture of a long column of armored cars the caption identified as Israeli.

The Israelis, the paper reported, have installed electronic devices and "sophisticated radar" at a number of points overlooking the Bekaa Valley from heights on the valley's west wall.

Western military analysts have confirmed increased Israeli military activity around the town of Aqurah, a place also mentioned in the L'Orient-Le Jour accounts.

At the same time, travelers reported that the Syrians were reinforcing their positions at the base of the mountain chain that forms the valley's east wall. Syrian reinforcements have been stepped up since the Israelis were reported establishing a lookout point at Aqurah, east of the coastal city of Jubayl, also known as Byblos.

The Israelis, according to L'Orient-Le Jour, have had heavy troop movements near the Bekaa Valley town of Rashayya and from Lake Qirawn north to the town of Mansoura. The Syrians have brought in as many as 40 additional tanks, including large numbers of the Soviet Union's most advanced T72 tanks, and taken up positions at the base of the Anti-Lebanon mountain chain between Lebanon and Syria and below the Israeli base at Aqurah, Lebanese sources say.

The Syrians also reportedly are deploying the T72 tanks along the Syrian-Lebanese border and have installed a multitude of surface-to-air missiles of the type that the Israeli Air Force destroyed in the Bekaa Valley during the early part of the fighting.

Western military analysts have stressed repeatedly that the Syrians consider the Bekaa Valley the first line of defense of their country. At points, the Syrian capital Damascus is only 10 miles from the border.

Israeli-made Merkava tanks and the Israeli Army's American-made M60 tanks reportedly are being deployed in the Bekaa by the Israelis in growing numbers. The Israelis have made no attempts to camouflage their tank positions or to dig them in. By contrast, extensive efforts have been made by the Syrians to hide their tank positions and they are well dug in to defensive positions, these reports say.

Both sides have engaged in heavy artillery and rocket duels in recent days. The duels have included rocket attacks on Israeli positions by the PLO guerrillas operating behind Syrian lines. Palestinian guerrillas who were not trapped in Beirut by the Israelis have been fortifying their positions around their camp south of Baalbek, L'Orient-Le Jour quoted Phalangist sources as saying, and transformed a Baalbek school into a military barracks.