KYIV -- The Ukrainian Security Service (SBU) says that searches of the Kyiv and Odesa offices of Russian Internet giant Yandex as part of a treason investigation found that company management had "illegally collected" personal data on local citizens.
The May 29 searches came less than two weeks after President Petro Poroshenko signed a decree banning Yandex and several other Russian sites, including the popular social networks VK -- formerly VKontakte -- and Odnoklassniki.
"Law enforcement agents found that the management of the company illegally collected, accumulated, and passed on the personal data of Ukrainian citizens," the SBU said in a statement on its website.
The data included information about users' "occupation, lifestyle, location, residence, work, leisure, sources and amounts of income, telephone numbers, e-mail addresses, and accounts in social networks.
"The information was transmitted to [Russian] security services for planning, organizing, and conducting reconnaissance, sabotage, and information-subversion operations in the country at the expense of Ukraine's sovereignty, territorial integrity, and inviolability," the statement said.
Treason is punishable by 12 to 15 years in prison in Ukraine and the confiscation of property.
Asya Melkumova, a Yandex spokeswoman, confirmed the searches and told RFE/RL: "We have no information about reasons of today's SBU action. Our lawyers are on the way to the offices. Yandex is ready to provide all information regarding its operations in Ukraine, according and limited by Ukrainian legal procedures."
WATCH: SBU releases video of Yandex search
According to Ukrainian IT news site AIN.ua, staff of both offices were ordered by the SBU to leave the premises while the searches were conducted.
Kremlin spokesman Dmitry Peskov told journalists he could not comment, saying, "We do not have complete information yet."
Yandex said it has been developing its services for Ukraine since 2005, providing its Ukrainian users with search engines, maps, navigation, online education, and other services.
“We have conducted our business in strict accordance with Ukrainian legislation and have focused on creating high quality local products," the company said in a statement. "While Ukraine is a small part of our business and the sanctions will not have a material negative impact on our consolidated results, we regret that this new legislation affects our 11 million Ukrainian users who rely on our services every month, and the thousands of Ukrainian organizations that use our technologies and services to grow and develop their businesses."
In signing the decree, which was published on May 16, Poroshenko cited the need to combat what he called Russian instruments of information warfare.
The move, which came at the request of Ukraine’s National Security and Defense Council and the SBU, added the companies to a long sanctions list that includes 1,228 individuals and 468 legal entities. It also sparked a public debate between critics who condemned it as censorship and a blow to freedom of expression and supporters who called it a long-overdue move in defense of national security.
Russia seized the Crimean Peninsula from Ukraine in March 2014, after sending in troops and staging a referendum widely denounced as illegal, and has given strong support to separatists whose war against Kyiv's forces has killed more than 9,900 people in eastern Ukraine since April 2014.