AMMAN, Jordan — Riot police officers stormed a pro-democracy rally here in the Jordanian capital on Friday, leaving one man dead, injuring scores of other people and dispersing with water cannons a 1,000-person tent camp set up the previous day to resemble Tahrir Square in Cairo.

Witnesses said the violence — the worst since demonstrations began in Jordan in January — came after some 200 pro-government counterdemonstrators using sticks and rocks attacked the protesters, who fought back. The riot police were called in, and they broke up the fighting as well as the tent camp.

The Interior Ministry said the man who died in the fighting, Khairi Jamil Saad, 56, an unemployed father of five, had suffered a fatal heart attack. But his son Nasser Saad said in an interview that the riot police had attacked and beaten them both. He said he saw his father’s body at the hospital. His teeth were broken, and he had signs of being beaten on his hands, legs and ears.

At least 100 injured demonstrators were at the hospital, and protest organizers said four of them were later arrested by the police.