BEIJING — The government put additional police on the streets and detained dissidents Tuesday as part of a security crackdown before the 25th anniversary of the crushing of pro-democracy protests centered on the capital's Tiananmen Square.
Police manned checkpoints, and officers and paramilitary troops patrolled overpasses and streets near the square.
The increased security comes on top of heightened restrictions on political activists, artists, lawyers and other government critics. Dozens have been taken into detention, forced out of Beijing or confined to their homes in other parts of the country.
"June 4 has come again and the plainclothes officers are here to protect us. I can't leave the house to travel or lecture," Jiangsu province-based environmental activist Wu Lihong said in a text message.
In an apparent sign of government nervousness, connections to the global Internet appeared to have been disrupted.
China allows no public discussion of the events of June 3-4, 1989, when soldiers, tanks and armored personnel carriers entered the heart of the city, killing hundreds of unarmed protesters and onlookers. The government has never issued a formal accounting of the crackdown and the number of casualties.
Beijing's official verdict is that the student-led protests aimed to topple the ruling Communist Party and plunge China into chaos. Protest leaders said they were merely seeking greater democracy and freedom, along with an end to corruption and favoritism within the party.
Authorities regularly tighten security ahead of June 4, but this year's suppression is harsher than in the past. Activists who previously received no more than a warning have been taken into custody and police have told foreign journalists they would face unspecified serious consequences for covering sensitive issues.
Despite China's discouragement, the crackdown is recalled with rallies and commemorations in Chinese communities worldwide, especially in Hong Kong, a former British colony that has retained its own legal system and civil liberties since returning to Chinese rule in 1997.