People staying near Beijing’s Tiananmen Square are being forced to remain inside their hotels for two 12-hour stretches this weekend so the Chinese military can practice for an upcoming parade that will celebrate seven decades of Communist rule.

“Thank you for choosing Grand Hyatt Beijing at Oriental Plaza for your upcoming visit to the capital,” reads an email sent to travel blogger Sebastian Powell, who posted the text of the message online. “October 1, 2019 will mark the 70th Anniversary of the Founding of the People’s Republic of China and to celebrate this important milestone, a number of very exciting government directed large scale events will take place in the direct vicinity of Chang An Avenue.”

It goes on to explain, “We understand that access to the hotel is likely to be partially or entirely restricted and foresee that traffic may also be affected.” But the words “likely,” “partially,” and “may” are doing a lot of heavy lifting here—the rehearsals have been going on since the beginning of September, and not only have hotels been completely locked down each weekend, but access to offices and apartments with views of the Avenue of Eternal Peace, which leads to Tiananmen Square, has been blocked, as well.

The email continues:

From Saturday 14 September (5:30PM) to Sunday 15 September (5:30AM) and from Sunday 15 September (5:30PM) to Monday 16 September (5:30AM)—it is likely that guests will not be allowed to come in and out of the hotel during this time. “From Saturday 21 September (5:30PM) to Sunday 22 September (5:30AM) and from Sunday 22 September (5:30PM) to Monday 23 September (5:30AM)—it is likely that guests will not be allowed to come in and out of the hotel during this time.

A similar lockdown last weekend was also announced with an email, but still caught many visitors by surprise, reports The Diplomat:

Transportation and accommodation schedules had to be hurriedly rearranged. Non-refundable, no-change policies on many flight tickets meant that travelers were forced to book new hotels outside the affected area, at the last minute, in order to be able to catch flights. Families visiting China to see the sights were suddenly told that they, and their children, could not go outside for at least 24 hours.

The anniversary event will reportedly show off the Chinese army’s most advanced weaponry, and is expected to be bigger this year than any such parade in the past. The largest one so far was held in 2015 to mark the end of World War II, in which 12,000 soldiers marched.

Speaking to reporters last month, army general Cai Zhijun insisted that the martial display should not be taken as a sign of aggression, according to Agence France-Presse, but rather as evidence that the Chinese army is “committed to safeguarding world peace and regional stability.”