BUENOS AIRES—Traditional taxi drivers in Argentina"s sprawling capital are mad as hell about competition from ride-sharing services and aren't, apparently, going to take it anymore — to the point of even "hunting" their rivals and physically attacking them.

For months now, the fight between Buenos Aires cabbies, on the one hand, and Uber and Cabify drivers, on the other, has become increasingly more violent, with Uber alone claiming some 650 incidents just this year. Assaults have targeted both cars and drivers, and included "weapons, acid, burning vehicles, shootings, ambushes, physical violence and threats," Uber reports.

Since Uber landed in Argentina two years ago, taxi drivers have not only staged protests, they've also mounted operations they call "hunts' to harass and intimidate rival drivers. Members of the 200-person Asociación Civil Taxistas Unidos, a cab-driver organization, admit that they've engaged in "trap and pursuit" operations to scare Uber drivers, but deny using physical violence.

"Some taxi drivers have taken the law into their own hands," said Marcelo Boeri, who heads the association. "We don't approve of what they do. But we understand them." Boeri also said that the state, by doing nothing to stop Uber from illegally stealing work from traditional taxi drivers, is an "accomplice in these attacks."

"I'd like to be Hulk and turn their car over. But I don't have time to be a gangster."

Attackers communicate among themselves, and sometimes carry weapons like pneumatic air rifles, sharp items to cut tires, or acid to spoil the car paint. In some cases they confuse Uber cars with private vehicles. There have even been incidents of attacks on cars carrying children.

One seasoned taxi driver who preferred not to share his name told Clarín that it's "easy" to spot an Uber car. "After driving a taxi for 27 years, I recognize them immediately," he said. "There's a passenger waiting while holding a cellphone. A car approaches, signals and the passenger gets in."

The man described how taxi drivers will then follow the Uber, using an application "that turns the phone into a walkie-talkie" to communicate among themselves. "If necessary we take over from each other along the way, while looking for a policeman."

"When I am there 50 minutes without a trip and I see them with passengers, I'd like to be Hulk and turn their car over. But I don't have time to be a gangster," he added, insisting that in his case, he's never taken violent actions. "I work 12 hours every day. The taxi is what keeps my home."

Uber has denounced the actions with the Inter-American Commission on Human Rights, which has received evidence on some 4,000 Uber drivers suffering harassment in Buenos Aires. According to the Commission, drivers are alleging officials and police are not investigating the violence or acting to impede its recurrence.

The Commission has called for respect for the human rights of Uber drivers, as reports indicate an increase in and intensification of attacks.