Security was high near the Ministry of National Defence in Beijing on Thursday morning after the authorities had earlier closed down several subway stations in the city for several hours with little warning. The heavy security presence near the ministry’s headquarters comes as the capital prepares to host a summit for China’s “Belt and Road” international trade initiative on Sunday and Monday. Several subway stations were closed in the centre of the city on Thursday morning, including one near the Chinese People’s Revolutionary Military Museum, close to Ministry of National Defence. In Dianmen West Avenue, where three subway stations were closed, a heavy police presence was seen at major intersections, with patrol cars and civilian-plate vehicles with uniformed officers inside. At some intersections dozens of police officers had been deployed. The closures had been announced just before midnight on Wednesday but no reason was given. The stations reopened just before noon, the subway authority said in a statement on its social media account. Police were withdrawn, too. 28 heads of state confirm attendance at China’s belt and road summit next month Police also appear to have stepped up patrols near the north entrance to Beihai Park in the centre of the city in the morning. Passers-by also faced questioning at security checkpoints set up near the headquarters of the government’s anti-corruption agency, the Central Commission for Discipline Inspection in Beijing. One subway station near Beihai Park and two near the anti-graft agency had earlier been closed. Others that were shut and later reopened included three near Tiananmen Square in the political heart of the capital. Earlier this month armed police were sent to guard entrances of subway stations in downtown Beijing. In a separate notice issued on Thursday morning, the subway authority announced that Olympic Green Station would be closed from Friday until Sunday night and it remained shut. It is unclear whether the subway closures and heightened security near the defence ministry are linked to the “Belt and Road” summit. The leaders of 29 countries from Asia, Europe, Africa and Latin America have said they will attend the event. The capital is no stranger to tightening security in response to protests, petitioners, terror attacks or any element viewed by authorities as a risk to political events. In February, military veterans, dressed in green and blue camouflage fatigues, protested outside the anti-corruption agency, the Central Commission for Discipline Inspection, for two days demanding better benefits. PLA veterans stage another protest in Beijing over unpaid benefits Beijing police announced earlier that traffic control measures would be put in place near northern Yanqi Lake where the summit would be held, plus the National Convention Centre, where the media centre is located and some related events will take place up to next Monday. The municipal government has urged residents to cut “unnecessary trips” and minimise car use during the two-day summit. All staff at municipal level government agencies, state-owned companies and government-linked organisations are banned from using private cars during the event. Public servants have been urged to stop driving their own cars to “set a good example” to the public. The municipal government has also told its agencies and state-owned companies not to hold any conferences on Monday.