AMMAN: Human Rights Watch on Friday urged Jordan to release activists detained last week during pro-reform demonstrations, criticizing the government's "toughening stand" toward their demands.

"The arrest by security forces of well over a dozen peaceful reform activists since September 7, 2012, signals the government's toughening stand toward demands for political reform in the kingdom," said HRW.

"The authorities should release all of those detained solely for the peaceful exercise of their rights to expression, association, and assembly," the New York-based watchdog said in a statement.

"The security services arrested activists in various parts of the country for peacefully protesting or calling for reform, in what appeared a concerted move by security and judicial authorities against opposition groups."

Those arrested last Friday include 10 activists from the southern towns of Tafileh and Karak, and seven from Amman.

Military prosecutors have charged six of them from Tafileh with "incitement against the regime" and "sowing sectarian sedition."

"The arrests show how shallow promises of political freedoms in Jordan are," said Christoph Wilcke, senior Middle East researcher at HRW.

"It is deeply worrying that Jordan is using laws against terrorism to prosecute peaceful activists."

Wilcke said the Jordanian government was "in full reversal mode against the modest gains in public liberties achieved by reform activists during the regional popular empowerment in 2011."

"The government should address legitimate concerns rather than trying to silence people who raise them," he said.

Jordan has been largely spared the kind of protests that have swept eastwards from Tunisia across the Arab world since early 2011, but it still sees regular demonstrations demanding political and economic reform and an end to corruption.