Saudi Arabia has announced one its largest anti-terrorist sweeps in years, arresting more than 100 people suspected of involvement in al-Qaida plots.  More than half of those detained are said to be from Yemen.

The Saudi Defense Ministry released a statement that those arrested are thought to be part of a terror network and two small cells that planned to attack oil and security targets in the kingdom.

The ministry said the suspects have ties to al-Qaida in the Arabian Peninsula, the Yemen-based off-shoot of Osama bin Laden's terrorist network.

That link - plus the naming of 51 Yemenis as being involved in the plots - comes as the Saudi government tries to reinforce the border with its southern neighbor, in part, to contain the spillover from one of Yemen's civil conflicts.

A Somali, an Eritrean and a Bengali are also among those arrested - a foreign element that provides a new challenge to the Saudi government, which has focused strongly on countering terror domestically.

Khaled al-Maeena is the editor-in-chief of the Saudi English newspaper Arab News. "Saudi Arabia, which has done so much with the rehab [rehailitation] program - getting people, inducing them to take the right path - suddenly finds itself with these people who are outside the pale of the law, are trying to commit acts of violence, creating confusion that leads to bloodshed," he said.

Saudi Arabia has taken pride in its efforts to bring militants back into society.  But there have been high profile set-backs, including a failed assassination attempt against a top security official last year by a supposedly reformed extremist.

The announcement on Wednesday of the pre-emptive arrests and confiscation of explosives is the latest in an otherwise largely successful attempt in recent years to prevent terror attacks in the country, the birthplace of many top al-Qaida leaders.

Special Project

More Coverage