Jordanian government officials have denied reports that the motorcade of King Abdullah II has come under attack.
A spokesman said news that a group of young men in the southern city of Tafileh had pelted his motorcade with stones and bottles was "baseless".
The alleged attack comes a day after King Abdullah announced major reforms, promising to relinquish his right to appoint prime ministers and cabinets.
Protests have called for electoral reform, more jobs and food price cuts.
An unnamed security official told Agence France Presse that the motorcade changed its route after the attack, during which no-one was hurt.
"Part of the king's motorcade was attacked with stones and empty bottles by a group of men in their 20s and 30s after the king's car entered Tafileh," the official said.
The official added that police had "tackled the infiltrators and made arrests".
'Lots of shoving'
But government spokesman Taher Adwan told the Associated Press news agency that there had been no attack.
"What happened is that a group of young Jordanians thronged the monarch's motorcade to shake hands with him," he said.
He explained that when police "pushed them away, there was a lot of shoving".
A Royal Palace official who accompanied the king also said that rather than being attacked, the king had merely been enthusiastically greeted.
"It was a gesture of welcome, not an attack," he said.
The king was reported to have been on a trip to look at infrastructure projects in the south of the country.
Though violence has rocked other countries across the Arab world, it has been rare in Jordan, where pro-democracy protests in recent months have generally been confined to relatively small demonstrations.