Bruno Placido, leader of the self-styled "self-defense" movement, described the 11 as the detainees accused by local residents of the most serious crimes, such as murder, kidnapping and extortion. He said they were turned over to state and federal officials.
The authorities will presumably weigh bringing charges against the detainees, but given that the suspects were taken and held with no legal authority, in some cases for weeks, any prosecution might prove difficult.
The government of the Pacific coast state of Guerrero, where the vigilante movement sprang up after a series of kidnappings in early January, said that Placido's group had agreed to turn over "the first 20" detainees, implying that more would eventually follow.
But Placido said an assembly of residents in the township of Ayutla would determine the next step.
The movement has spread to about a dozen towns, with farmers wearing ski masks and bearing old hunting rifles and shotguns setting up roadside checkpoints to ask passing motorists for identification. The IDs are checked against handwritten lists of "bad guys" that the movement wanted to detain.
At an assembly of townspeople last week, the 53 detainees were paraded before local residents and plans were announced to bring charges against them and try them before a similar town assembly, with no clear provisions for what kind of defense they would be allowed to mount.
That drew sharp criticism from human rights officials and activists, who said the farmers movement was taking the law into its own hands and could ride roughshod over the rights of the accused.
The situation grew more complicated when local media said the vigilantes might be trying to detain activists from other political groups, and tensions rose between the vigilantes and the more established "community police" that operates in dozens of Guerrero towns. The community police are better regulated and partially recognized under state law.
State and federal authorities have so far tolerated the movement, despite the fact that its members have turned back government human rights officials seeking to check on the detainees condition.
On Friday, Interior Secretary Miguel Osorio Chong told the Milenio TV network that the government will seek to "regularize their situation so that they can continue to assist authorities."
The vigilantes have been demanding uniforms, salaries and official ID cards to continue their work, while authorities have been trying to get them to stop wearing masks and turn checkpoint duties over to police or soldiers.
The sight of a dozen or so masked, armed men stopping cars on rural roads can be intimidating, and a pair of tourists from Mexico City visiting a local beach were shot at and slightly wounded when they failed to stop at one such checkpoint last week.
Despite such problems, authorities have been loath to crack down on the vigilantes, given the government's own inability to bring security to Guerrero state, which is home to the troubled beach resort of Acapulco, where six Spanish tourists were raped by a gang of armed men Monday. Guerrero Gov. Angel Aguirre said authorities "are very close" to making arrests in that case.
The vigilantes say drug gangs from Acapulco have been coming up into the hills around Ayutla to kidnap people and demand "protection" payments.