World Notes BRITAIN

If you can't buy it, bomb it. That seems to be the philosophy of a shadowy group of Welsh nationalists who exploded fire bombs in five central London real estate offices last weekend. They call themselves the Sons of Glendower, taking their name from Owen Glendower, leader of a 15th century Welsh rebellion against the English, and are thought by the authorities to number little more than half a dozen.

The group charges that affluent English home buyers seeking vacation retreats are snapping up Welsh country cottages and pricing out the locals. In retaliation, the Sons have been setting fire to purchases made in Wales by outlanders: more than 140 arson attacks since 1979 have resulted in damages totaling almost $1 million. Official nationalist groups in Wales dissociate themselves from the property extremists.

Although nobody has yet been killed or seriously injured, police worry about the increasing sophistication of the incendiary devices being used. Warned Scotland Yard spokesman Neil Schofield last week: "If they've decided to step up the campaign in London, it's something we have to take very seriously."