Palestine Liberation Organization Chairman Yasser Arafat posted armed guards around his offices in Damascus today to protect himself and his supporters from dissident officers serving in the Fatah guerrilla movement in eastern Lebanon.

The enhanced security came a day after dissidents opposed to Arafat's moderate policies responded to his cutoff of aid and supplies to them by seizing food, ammunition and equipment supply depots on the outskirts of Damascus.

According to reports reaching here, the level of tension in the conflict has risen, despite almost daily visits by Arafat to PLO positions in eastern Lebanon's Bekaa Valley and to northern Lebanon to quell the uprising.

"The revolt is intensifying," a close aide to Arafat told a reporter for Reuter in Damascus today.

Arafat aides said rebels shot their way into the depots, wounding three people, but a spokesman for the dissidents said the takeover was peaceful.

The uprising, which began more than three weeks ago in Fatah, the largest faction in the PLO and Arafat's main base of support, has presented Arafat with a serious challenge to his leadership.

It has added yet another kink in the tangled and volatile situation here. In response to the challenge for leadership in the PLO, Arafat has spoken about the inevitability of war, an assertion that seems aimed at rallying his fighters but also has the effect of heightening tensions.

The indications are that Syria, despite its own warnings of war, has stringently kept in check PLO fighters behind its lines, although they have bragged about breaking through the Syrian lines to launch hit-and-run attacks against Israel.

One such attack, in which an Israeli soldier was killed, occurred Friday, but the indications were that the Israelis were refraining from retaliatory action. That was taken as a good sign among optimistic analysts watching the center stage of the conflict, the tension along the front lines of Israel and Syria in the Bekaa.

Israel continued to send tanks and reinforcements into Lebanon today. Local radio reported that there was antiaircraft fire at Israeli planes, which reportedly were increasing their reconnaissance flights over Syrian-held positions. The reports said the firing came from PLO positions around Tripoli. Israeli spokesmen did not comment on the reports.

Lebanese television reported that Israeli gunners and Syrian artillery units exchanged shell fire across the cease-fire line in the Bekaa, killing one Lebanese and wounding another, The Associated Press reported. Israeli security sources said the clash was minor, lasting for about 20 minutes with only a few rounds exchanged.

Syria's uncharacteristic announcement yesterday that it had ended the spring maneuvers, which had raised alarms, was confirmed today by a senior Israeli military source, according to an Israeli radio boardcast.

The radio report said Israel's armored corps commander, Gen. Moshe Bar-Kochba, toured the front line today and said there were no signs of unusual activity on the Syrian side.

"We must assume that the Syrians, seeing that our forces are prepared, will not take hasty decision," he told Israeli Army radio.

A White House spokesman confirmed Sunday that Syria has ended its spring military exercises in Lebanon, but said the United States is still concerned about the possibility of a conflict between Syrian and Israeli forces, AP reported.

Deputy press secretary Larry Speakes said: "Our concerns on the escalation of troop strength remain the same." He called the situation "an uneasy peace" that could be disrupted by provocation.