Four protesters against the war in Lebanon were arrested on Sunday after a security breach at a Scottish airport, police said.

The three women and a man got through a fence at Prestwick Airport, near Glasgow, and ran on to a runway, according to media reports.

They were thought to be protesting at the use of the airport by US planes carrying munitions to Israel, the reports said.

"Four protesters... were arrested and are currently detained in police custody following an alleged breach of security at Prestwick Airport," a police spokeswoman said.

The women were aged 52, 45 and 36 and the man was 25 years old, the spokeswoman said. She did not name the suspects and had no further details.

The US flights came to light on July 26 when Foreign Secretary Margaret Beckett said the British government would make a formal complaint to Washington over its use of Prestwick for ferrying bombs to Israel.

Beckett said it appeared the United States did not follow correct procedures when transporting arms to Israel -- engaged in a war with Hizbollah guerrillas in Lebanon -- via Britain.

British media reported that aircraft carrying "bunker-busting" bombs from the United States to Israel had refueled at Prestwick in July.

The United States denied it had broken British air transport procedures, but President George W. Bush later apologized to Prime Minister Tony Blair for failing to follow proper procedures, according to Blair's spokesman.

Two more US planes carrying unspecified "dangerous goods" to Israel refueled in Britain in late July with official permission. But, as demonstrators gathered at Prestwick, they diverted to a British air force base.