BEIJING - Chinese police have cracked two major diploma counterfeiting groups and detained at least 21 suspects, said railway police on Friday.

Shanghai railway police raided two locations involved in counterfeiting diplomas and detained 21 suspects in late July, said a statement from the railway police division of the Ministry of Public Security.

Police confiscated more than 40,000 fake seals of government departments and other institutions, and more than 50,000 fake diplomas at the locations, the statement said.

Last week, Chengdu railway police raided another counterfeiting location and seized about 2,700 fake diplomas and 3,190 fake seals following a lead from a train passenger using a fake identification card, it said.

The statement did not reveal how many suspects were detained in the second raid.

Since July, railway police have stepped up patrols on trains and railway stations, targetting diploma and ID counterfeiting crimes.