The Jordanian government yesterday used armed forces to break up demonstrations here by Palestinian youths protesting Israel's invasion of Lebanon.

The demonstrators, mostly young Palestinians, shouted slogans against King Hussein and Syria's President Hafez Assad, calling on them to use their armies to aid the Palestinians in southern Lebanon.

Using teargas and firing bullets into the air, Jordan's security and army troops broke up the demonstrations. An unspecified number of persons were injured yesterday while 30 civilians and eight policemen were hurt when the Palestinian agitation began Monday.

Security has been stepped up in most areas of Amman, and jeep-mounted machinegunners flanked the American embassy yesterday morning after faculty members of the normally placid University of Jordan issued statements over the weekend calling on the Arab world to attack imperialist and "especially American interests in the Arab world."

Extra police units could be seen in parts of Amman, and armored personnel carriers took up positions at some strategic intersections.

The government has issued a strong statement banning demonstrations and saying that any new ones would be put down using all necessary force. It called on citizens to show their support for the Palestinians in southern Lebanon by sending material aid and donating blood.

Students at the University of Jordan went on strike this week and most predominantly Palestinian schools and training centers were also on strike yesterday in a show of solidarity with the Palestinians.

Hundreds of persons have replied to calls for blood as well as to volunteer to aid refugees in Lebanon.

In the commercial and middle-class residential quarters of Amman, life went on as usual, although the rattle of machineguns being fired into the air to scare off demonstrators could be heard.