Saudi Arabia yesterday announced the arrest of 42 suspected Islamist militants in raids across the kingdom, a day after police killed six men in a shoot-out in Riyadh.

An Interior Ministry statement said 15 of the suspects were arrested after the clash early on Friday in which one policeman was killed and 17 others were wounded. State television said that four men wanted by security forces, including an Iraqi, were arrested in a raid yesterday at a desert hideout in the northeastern town of Hafr al-Baten.

The raid led to the arrest of nine Saudis "involved in terrorism" who were part of the same group, it said adding that weapons and documents were seized during the operation.

The statement also said that 27 Islamists had been arrested last month in the capital Riyadh, the Muslim holy city of Mecca, the Eastern Province and the northern border region, including 24 Saudis, two Somalis and an Ethiopian.

It said the 27 men were involved in "suspicious activities" connected to radical Islamist groups. A security source told Reuters the arrested men and the six killed on Friday were part of a wider militant cell, numbering around 50 people, that had been broken up.

In Friday's incident, police said the three-hour clash began after they surrounded a house to prevent planned attacks. The authorities have given no details of the plans. A wounded suspect arrested during the clash on Friday is being interrogated, the statement said without giving further details.

Islamist militants allied to Saudi-born Osama bin Laden's Al-Qaeda group have been waging a violent campaign aimed at toppling the US-backed monarchy and expelling Westerners from the birthplace of Islam.