Palestine Liberation Organization Chairman Yasser Arafat returned to Damascus today in what appeared to be a calculated effort to show that he is not afraid to be in the Syrian capital at a time when he is accusing that government of providing tank support for a mutiny against him.

Arafat told reporters he did not expect to see Syrian President Hafez Assad or other officials in Damascus, according to news agency reports. He met immediately with the Soviet ambassador, however, and received a message from Soviet leader Yuri Andropov, which aides described as important.

Speculation here was that it was a response to his urgent appeal to the Soviet Union and Arab leaders for help. Palestinian sources said Arafat would probably meet with PLO factions that have remained neutral in the two-month-old revolt within Fatah, the PLO's main party and Arafat's base.

In a meeting with a small group of reporters early Friday morning, Arafat said a convoy of 12 cars carrying his supporters from Damascus to the northern Lebanese port city of Tripoli had been ambushed, The Associated Press reported. At least 12 of his supporters were injured in the attack near Homs, about 100 miles from Damascus, Arafat said.

Earlier today, before leaving his provisional headquarters in Tripoli, Arafat, surrounded by heavily armed bodyguards, met reporters in an olive grove.

"My problem is clearly and obviously with Syria, not Abu Musa," the leader of the rebellious faction, he said. "I am trying not to close the last window with the Syrians, but the matter is now up to them. The Syrians want to decide for the Palestinians. That decision I will not give to anyone. I am still holding the olive branch in one hand and the gun in the other."

Arafat repeated allegations made by aides yesterday that in the past two days Syrian forces had cut off supplies to his men and that Syrian tanks had surrounded his military positions in eastern Lebanon.

Arafat and top aides abruptly left Damascus early Tuesday morning after mutinous forces, who he later said were backed up by Syrian soldiers, overran some of his military positions in eastern Lebanon's Bekaa Valley.

Arafat's aides, who have accused Syrian authorities of various crimes, including an assassination attempt on a senior loyalist, had said Arafat would not return to Damascus until Syria stopped pressuring the PLO.

But Arafat had hinted broadly when talking to reporters in Tripoli this morning that he might soon travel back to Damascus.

Asked about the concern of his aides that his life was in danger, Arafat said, "From the moment I started this revolution, I knew it was not a picnic."

Arafat's military chief, Khalil Wazir, said the guerrillas have been ordered to give up no more territory to the mutineers. "Our fighters are trying to avoid firing, but if they come again, the order is every fighter to defend his place," AP reported.

The reassembling of the PLO leadership in Tripoli this week has added yet another complication in the deteriorating Lebanese crisis and led to new worries in Beirut.

Israeli military authorities, who fear that the Palestinians' internal conflict could cause both sides to step up attacks against Israeli soldiers, have aggressively sought information about it. Today, Israeli officers set up portable offices alongside their front-line checkpoint on the Beirut-to-Damascus highway and interrogated journalists returning from the Bekaa Valley about the PLO situation before allowing them to pass.

Lebanese President Amin Gemayel and Prime Minister Shafiq Wazzan met today to discuss concerns that the PLO political and military operations disbanded in last summer's evacuation from West Beirut were being resurrected in Tripoli.

Yesterday, Lebanese authorities shut down the Palestine Research Center, the PLO's last remaining political office here. The center's director, Sabry Jiyris, and two military officers there have been held by Lebanese authorities since Sunday. Lebanon accuses them of participating in plots leading to a series of bombings here. Military prosecutor Assad Germanos is seeking to have them expelled.