* Sixty-two suspects detained, Interior Ministry says
* Round-up reflects fears of radicalisation from Syrian war
* Concern peaceful dissidents being targeted -rights groups (Recasts throughout with added background and context)
By Rania El Gamal and Yara Bayoumy
RIYADH, May 6 (Reuters) - Saudi Arabia has detained 62 suspected al Qaeda militants with links to radicals in Syria and Yemen who were plotting attacks on government and foreign targets in the kingdom, its Interior Ministry said on Tuesday.
The world’s No. 1 oil exporter is increasingly concerned that Syria’s civil war is radicalising more of its own citizens and has announced tough new measures to counter militancy.
The 62 represent the largest group of people said by authorities to have been detained on suspicion of Islamist militancy for at least two years in the conservative Islamic kingdom, which has imprisoned thousands over the past decade in its battle against al Qaeda.
Some 35 of the detainees had previously been held by the Saudi authorities on security charges before being released, Major General Mansour Turki, the Interior Ministry’s security spokesman, told a televised news conference.
“They swore allegiance to their warlord and started in constructing components of the organisation, means of support and planning for terrorist operations targeting government installations and foreign interests and the assassination of security personalities,” he said.
He said the group had links to the al Qaeda-affiliated Islamic State of Iraq and the Levant (ISIL), which is both a powerful force among rebels in Syria’s civil war and an anti-government combatant across the border in turbulent Iraq.
International rights groups have said some of the thousands of people detained and jailed by Saudi Arabia on security grounds over the past decade were peaceful dissidents, something the authorities deny.
The groups have also voiced concern at a new “anti-terrorism” law that gives the authorities wide scope to detain and jail people as militants for criticising the ruling family.
Turki said monitoring of social media played an important role in uncovering the group of 62, and had shown how al Qaeda members in Yemen and Syria were communicating with each other in coordination with members of the group inside Saudi Arabia.
The authorities found a laboratory to make explosives and seized funds worth nearly one million Saudi riyals ($266,000) intended for the cell, Turki said. State television showed dozens of seized mobile phones, laptops and tablet computers.
He said the cell comprised 59 Saudis, a Pakistani, a Yemeni and a Palestinian, and that one detainee was the group’s leader.
Turki added that the authorities were still seeking another 44 people suspected of having links to the group.
While Saudi Arabia is a leading supporter of the insurgency against Syrian President Bashar al-Assad, it also fears the conflict could reinvigorate a threat from militants within its own borders.
The Interior Ministry has said that anger at the Syrian conflict has spurred a surge in online militancy, and that it fears Saudis who travel to Syria to fight with the rebels might join al Qaeda and return to the kingdom to carry out attacks.
An al Qaeda insurgency inside Saudi Arabia from 2003-06 was mainly led by veterans of civil wars in Afghanistan and Iraq, and after it was crushed its survivors fled to neighbouring Yemen where they founded a new branch of the movement.
Al Qaeda has thrived in south Yemen since then, exploiting weak government and widespread poverty, but a Yemeni government offensive ousted militants from their main regional stronghold on Tuesday, the Defence Ministry said.
In February, King Abdullah issued a decree that any Saudi who travelled abroad to fight faced three-20 years in prison and that any who supported a militant group would be jailed for five-30 years. ISIL was named as a banned terrorist group.
Separately, a group calling itself the al-Zaraqwiyya Battalion” after the late Iraqi al Qaeda leader announced on Twitter it had been set up in Saudi Arabia to target Shi‘ite Muslims, SITE monitoring reported on Tuesday.
The group said “legitimate targets” included Shi‘ite gatherings, their homes and cars, and individuals who defend them. Shi‘ism is seen as heretical by al Qaeda. Most Saudi Shi‘ites live in the country’s Eastern Province.
$1 = 3.7505 Saudi Riyals Writing by Angus McDowall in Riyadh, editing by Mark Heinrich