The Chilean government has arrested and exiled a dozen prominent opposition political leaders to remote mountain villages in what observers here see as the first dose of a political crackdown hinted at by President Augusto Pinochet after his referendum victory 12 days ago.

The 11 men and one woman were arrested Friday at what a government spokesman said was a "clandestine political meeting' and exiled over the weekend to scantily populated shepherd villages, all over 10,000 feet in altitude, in the barren Andean range separating northernmost Chile from Bolivia.

All 12 are members of the centrist Christian Democratic Party, Chile's largest single party and the strongest opposition to the military government. All political activity was banned by the military government after the 1973 coup and leftist parties were outlawed. The Christian Democratic Party was banned last March after holding a party election but no reprisals were taken against party leaders. Party activities and private meetings have been unofficially tolerated until now.

The government gave no reasons or charges for the deportations and cited only the powers to arrest and deport provided for by the state of siege decreed in September 1973. The 12 were arrested by regular detectives at an office in central Santiago.

The pro government press and two television stations had apparently been tipped off about the raid and reporters and cameramen appeared on the scene about 10 minutes after the detectives.

Political activity is banned by various decrees of the military junta but the term has never been precisely defined and no one has ever been prosecuted in Chilean courts under the decree.

The state of siege deportation procedure is not subject to scrutiny by the civilian courts.

The Christian Democrats led the movement two weeks ago to vote "no" in the referendum as a sign of disapproval of Pinochet and the military regime. Results announced by the government show 75 per cent of "yes" votes for a resolution supporting the Pinochet government against foreign criticism about the status of human rights here.

The Christian Democratic Party protested the results and the government-controlled vote count on the grounds that the state of siege and a government-mounted publicity barrage constituted unfair psychological pressure on voters.

In a speech after the voting, Pinochet announced that elections, a Christian Democratic demand shared by the underground leftist parties, woudl nto be held for at least 10 years. In a reference directed at the intense opposition activities before the vote he warned: "Mr. Politician, it's all over for you."

Those deported include Tomas Reyes, about 64, the former president of the Chilean senate and second to party president Andres Zaldidar in the party hierarchy, and two former members of the chamber of Deputies. Also deported was university student leader Guillermo Yunge, one of the leaders of the first public street protests two weeks ago against the Pinochet regime in the days prior to the Jan. 4 referendum.

The former deputies are Andres Aylwin, a lawyer who has worked since the coup in human rights defense cases and Samuel Astorga. Two others in the group are Juan Manuel Sepulveda and Hernan Mery, leaders of the Christian Democrat-oriented opposition labor federation known as the Group of Ten the others arrested are Delisario Velasco, Elias Sanchez, Enrique Hernandez, Juan Reyes Saldias and Georgina Aceltuno.