Undated (AP) _ Charles Glass, the American journalist who escaped Tuesday from captivity in Beirut, said he is convinced that his captors did not permit him to escape because they had recently become even more severe with him.

In an interview with ABC News from a Syrian television studio in Damascus, Syria, Glass said he wrote notes in his own blood pleading for rescue, and that a gun was pointed at him when he made a videotape in which he said he was a spy.

Glass said he had found his 62 days in captivity hard to bear.

Thinking of hostages Terry Anderson and Tom Sutherland, who have been held since 1985, Glass said: ''I think 2 1/2 years would be impossible for them and their families. It's unconscionable.''

''It's too much for them to bear,'' added Glass.

''I think of the pain that my family endured for this relatively short period, and compare it to the ... misery of these other families, who've been going through this for such a long time, and something has to be done.''

Glass said he had gone to Beirut in the belief he would be safe because of the Syrian military presence in West Beirut. ''But I was wrong and certainly it was probably the stupidest mistake I've made in my life,'' he said.

Glass said he had been chained at the wrist and the ankle. Unbeknownst to his captors, he said, he was able to stretch the chains and slip them on and off.

ABC anchorman Ted Koppel asked the 36-year-old Glass whether he had any suspicion that his captors allowed him to escape, as a Syrian source had suggested.

Glass said he understood there was strong pressure from the Syrians to obtain his release, and that ''my escape may simply have jumped the gun by a few days.'' But he said his captors had not made his escape easy.

''In fact, they'd made things much harder over the previous couple of days by shortening my chain, and making it impossible for me even to get near to the shutters or to that ... large cupboard, which I had to move,'' Glass said.

''So, as far as they knew, the chains were tight and it was impossible for me even to move and ... even to exercise. Things were getting much, much worse for me, rather than better.''

Glass said two guards were on duty at night in the Beirut apartment where he was kept. Before he made his escape on Tuesday morning, he said, he could hear the guards snoring.

''I was able to sneak out of my room by moving a very large cupboard, very slowly, and as quietly as I could, and sneaking out onto the balcony through the shutters, which had been blocked by the cupboard,'' he said.

''And when I went out on the balcony, I thought, perhaps, I could jump to another balcony or get to another apartment. But the balcony was blocked in such a way that it didn't lead to any other balconies, and I would have had to jump about seven stories if I wanted to get to the ground.

''So I came through another door ... of the balcony, into the kitchen, into the central corridor of the apartment and out the front door. There was a key in one of the locks. There were three locks on the front door; two of them were bolt locks which I could slide, and one had a key which I had to turn three times, very quietly, because the bedroom of the guards was right next to the front door, and I could still hear them snoring.

''I opened the door finally very quietly, slid out, took the key with me, locked them in, and ran down the seven flights of stairs and out into the road.''

At one point during his captivity, Glass said he had pushed notes through a fan in a bathroom. The notes, in Arabic, French and English, said: ''I am Charles Glass. I am hostage.'' The notes promised $10,000 to anyone who would help him, and included numbers to contact, he said.

''I began writing the notes in my own blood because I didn't have a pen,'' he said. Later, he was given a pen to write to his wife and he kept that, he said.

''One day, one of the guards outside discovered one of these notes and they called for a chief, on their walkie-talkie, who then came, about an hour later, and said, 'if you make a mistake like that, again, we're going to kill you.'''

After that, he said, he was moved to another place.

Glass, on leave of absence from ABC to research a book on Lebanon, was kidnapped June 17 with Ali Osseiran, son of Lebanon's defense minister, and his bodyguard-driver by 14 gunmen in south Beirut.

His captors, who identified themselves as members of the previously unknown Organization for the People's Defense, released the two Lebanese after a week.

The kidnappers released a videotape on July 17 which showed Glass reading a statement in which he said he spied for the Central Intelligence Agency.

Glass said he was told that if he did not make the tape, he would never see his family again. He said a gun was pointed at his head while he made the tape.

''I did everything in that tape to convince my friends at ABC, particularly, that this was not me, these were not my words,'' Glass said.

''By reading the text, ungrammatical as it was, by speaking in a Southern accent so that they would know I was in south Beirut, by pretending to be more afraid than I actually was so that they could see that these were not my words.

''And I held the paper in such a way - and I don't know if it was in the fram - that my fingers were crossed as I held the paper, so that you could see that these were not my words,'' Glass said.