London said Monday it was calling on its nationals planning to travel to Saudi Arabia for the annual hajj to make note of safety advice. The British Foreign and Commonwealth Office advised citizens planning the November pilgrimage to \"prepare carefully and follow travel safety advice\" as they prepare to make their journey. In its latest travel advisory for Saudi Arabia, London said all British nationals should exercise vigilance and avoid large gatherings and demonstrations. The advisory noted Saudi authorities convicted more than 700 people on terrorism charges stemming from last year\'s pilgrimage. \"We are aware that the Saudi authorities are concerned about an increased threat of terrorism in the kingdom,\" the warning read. Last week, Saudi officials blamed foreign interference for an attack in the eastern Shiite city of Awwamiya, in which assailants on motorcycles used machine guns and Molotov cocktails. The official Saudi Press Agency reported that 11 members of the country\'s security force were injured in the attack. The Saudi report goes on to say the attack was carried out by \"weak-minded people\" who were likely influenced by outsiders. The hajj is an annual pilgrimage to Mecca, Saudi Arabia, and is considered a religious duty to be carried out at least once by every Muslim who has the means to make the trip.