AMMAN, Jordan — Fearing the fallout and the spread of the uprising in Syria, Jordanian officials have recently moved more forcefully to restrain opponents of the Syrian government who have fled to Jordan, activists here say.

A Syrian opposition leader from Dara’a said that intelligence agents tried to dissuade him from returning after a recent trip outside the country. Jordanian airline officials demanded he buy a ticket to go on to Damascus before he boarded the plane. In another case, an artist once imprisoned in Syria said that since arriving in Jordan in March, he had been interrogated four times by intelligence agents who warned that he would be sent back to Syria if he engaged in conspicuous activism against the Syrian government.

The episodes reflected Jordan’s perennially anxious state, battered by cycles of crises in the region, fearful of stronger neighbors and dependent on others for financial and military support. In recent weeks, Jordanian officials and commentators have made dire predictions that refugees could overwhelm the country as the war worsens, strangling Jordan’s fragile economy and straining its resources.

But officials are especially concerned that the uprising could unsettle the country’s already turbulent politics. Small but persistent demonstrations over the past year have focused on government corruption, and have resulted in increasingly bold expressions of anger directed at the country’s monarch, King Abdullah II.