By Margarita Antidze
TBILISI (Reuters) - Azerbaijan has arrested dozens of President Ilham Aliyev's opponents in a pre-election crackdown that has more than doubled the number of political prisoners in the former Soviet republic, a rights watchdog said on Tuesday.
The Azerbaijan-based Human Rights Club said 142 journalists, religious activists and human rights defenders were now being held in prison on political grounds, a week before an October 9 presidential election that Aliyev is expected to win.
That compares with 60 prisoners the group said were being held on political grounds in January in Azerbaijan, an oil-producing country of around 9 million people.
"The authorities seem intent on silencing all voices of criticism and dissent in the run-up to the election," said Rasul Jafarov, the group's chairman.
It said Aliyev had been emboldened to crack down on opponents since the defeat of a resolution in January by the Parliamentary Assembly of the Council of Europe that was intended to put pressure on Azerbaijan over human rights.
"Members of PACE must take action to address their failure to hold the Azerbaijani government accountable for these serious violations ... by calling for the immediate release of all political prisoners in the country," said Human Rights Club Advocacy Director Rebecca Vincent.
Azerbaijan, a mainly Muslim country in the South Caucasus, dismisses accusations of human rights abuses and says its citizens enjoy full democratic freedoms.
The group added to concerns voiced by the Organisation for Security and Cooperation in Europe (OSCE) and Reporters Without Borders, who on Monday condemned the imprisonment of prominent Azeri journalist and human rights activist Khilal Mamedov.
He is serving a five-year jail sentence on charges of treason, drug possession and "fomenting national strife".
Mamedov, editor-in-chief of a newspaper in Azerbaijan's southern ethnic-Talysh region, was arrested in June 2012. His lawyers have called the case against him "absurd".
Rights groups accuse Aliyev, in power since his father Heydar's death in 2003, of curbing dissent and freedom of speech in Azerbaijan, which is criss-crossed by oil and natural gas pipelines and exports fuel to Europe.
Azerbaijan's strategic location between Turkey, Russia and Iran and its role as a transit route for U.S. troops to reach Afghanistan have cushioned it from Western criticism, rights activists say.
(Writing by Margarita Antidze; Editing by Gareth Jones)