LONDON: British prosecutors on Tuesday charged a 24-year-old man with planning an attack on US military personnel in Britain, following an investigation into terrorism.

Junead Ahmed Khan and his younger 22-year-old uncle Shazib Ahmed Khan were also charged with planning to join militants in Syria, the Crown Prosecution Service (CPS) said.

The preparation for the alleged attack is said to have taken place between May and mid-July.

No other details were immediately available. The two men are accused of planning their trip to Syria between August 2014 and May 2015.

“It is alleged that Junead Khan and Shazib Khan had been planning on traveling to Syria to join the proscribed organization Daesh,” said Deborah Walsh, deputy head of counter-terrorism at the CPS.

“It is further alleged that Junead Khan was planning a terrorist attack on US military personnel in the UK and he has been charged with an additional terrorism offense to reflect this.”

The two men were arrested on July 14, along with another man in his 30s, who was later released without charge.

“The arrests and searches were part of an ongoing investigation into terrorism,” police said.

In an unrelated development, prosecutors say a British software engineer tried to buy enough ricin over the Internet to kill hundreds of people, and planned to test it by killing a small animal.

Mohammed Ali allegedly contacted a seller in the US about buying 500 milligrams of the poison for $500. The contact, who used the names Dark Mart and Psychochem, was an undercover FBI agent.

Ali was sent a toy car containing a harmless powder that he believed was ricin.

Police found a list on his computer with entries including “paid ricin guy” and “get pet to murder.”

Ali denies attempting to possess a chemical weapon.

Prosecutor Sally Howes told jurors at London’s Central Criminal Court on Tuesday that police found no evidence suggesting Ali was associated with terrorist activities or organizations.