The diplomats have been declared persona non grata in Lithuania "without any reason", it says in a comment on China's Foreign Ministry's website.
Lithuania's actions are making the countries' relations increasingly strained, according to Chinese statements:
"China urges Lithuania to immediately stop undermining China's sovereignty and territorial integrity, and stop creating difficulties for bilateral relations."
Lithuania announced this on Friday and made it clear that the three Chinese had a week to leave the country. Otherwise, the Lithuanian Foreign Ministry has only referred to the Vienna Convention and its provisions for diplomats' stays in other countries – and warned that decisions will be made about more Chinese diplomats in the near future.
All this is happening in a situation where a Chinese ship is suspected of involvement in suspected sabotage against the cables on the bottom of the Baltic Sea – between Sweden and Lithuania – that broke last week. Neither Lithuania's nor China's Foreign Ministry mentions it in this context, however.