Western tourists in China have been warned of possible attacks around Christmas in Sanlitun district, a popular shopping area and night spot of Beijing.
In separate warnings issued, the UK, US, and French embassies have urged their respective citizens to take care while visiting Sanlitun, without elaborating further.
It is said extremists from the restive Xinjiang Uyghur autonomous region are likely to target tourist spots to gain attention.
Following the embassy warnings, Beijing police have issued a yellow alert and armed police are standing guard in Sanlitun.
There will be increased security checks in shopping areas. Rubbish bins in public areas will be checked every 30 minutes.
The trendy Sanlitun bar and restaurant area had witnessed occasional fights. In August, a lone attacker stabbed a French man and a Chinese woman there. The woman died.
Although Christmas is not a holiday in China, people celebrate it and exchange gifts.
Xinjiang has seen violent attacks. Beijing blames them on Islamist militants and separatists of Xinjiang Uyghur region who are trying to establish an independent state called East Turkestan.
Last July, dozens were killed or hurt in attacks on a police station and government office by a gang armed with knives.
Earlier in the year, more than 60 people were killed in separate attacks on a market and a train station.