MOSCOW (Reuters) - Russia's economy ministry said allegations against economy minister Alexei Ulyukayev, who was detained overnight and charged with bribery, require serious investigation.

"This is strange and surprising news for us," Ulyukayev's spokeswoman Elena Lashkina said on Tuesday.

(Reporting by Darya Korsunskaya; writing by Maria Tsvetkova; editing by Vladimir Soldatkin)