The protesters and the security forces in Homs are locked in a

protract

ed and violent battle of wills. For days now, residents have been saying that they are frightened and stuck in their homes, listening to gunfire outside. On the streets, there are checkpoints and a heavy security presence as the authorities seek to arrest protest organisers. It seems that some of the violence in Homs has been sectarian with the city's Sunni and Alawite communities clashing. Both the government and opposition accuse each other of encouraging sectarian violence.

Nato says it's investigating how its computer network was hacked. A group of international hackers calling themselves Anonymous said they had

breach

ed Nato security and downloaded hundreds of confidential documents. The cyber attack comes days after 21 suspected members of Anonymous were arrested in the US, Britain and the Netherlands. Caroline Hawley reports.

According to Anonymous, its hackers have now laid their hands on one gigabyte of restricted data. The documents they posted online don't appear to contain information that will concern Nato too much. But a Nato official condemned any leak of classified documents, saying they could potentially

endanger

security. A splinter group of Anonymous has previously hacked the website of the CIA and of Britain's Serious Organised Crime Agency. Taunting Nato on Twitter, Anonymous says it has more of what it calls the organisation's "delicious data".