By Pavel Polityuk

KIEV (Reuters) - Ukraine is banning flights by Russian airlines from Oct. 25 as part of a wave of sanctions against Russia over its support for separatists in the east of the country, the government said on Friday.

Kiev said last week it was imposing restrictions on more than 90 companies or groups, mostly from Russia, and including airlines Transaero and Aeroflot , the national flag carrier.

Spelling out the details of the sanctions, Prime Minister Arseny Yatseniuk told a government meeting: "In accordance with a decision by the Security Council, the government of Ukraine is adopting a decision to ban flights by Russian companies, primarily Aeroflot and Transaero, to Ukraine."

The government website quoted him as saying: "Russian planes with the Russian tricolor have no business in Ukrainian airports."

He added that any Russian planes carrying military hardware or troops had also been banned from flying over Ukrainian territory.

The Ukrainian aviation authority later said the ban would be enforced from Oct. 25.

Ukraine has accused Russia of sending arms and troops to help pro-Moscow separatists fighting its soldiers in the east of the country, in a conflict which has killed nearly 8,000 people since April 2014. Russia denies involvement.

Ukraine has also imposed sanctions on around 900 individuals for what it calls reasons of national security.

Aeroflot said it had not received formal notification of the decision from Ukraine.

"Only when and if Aeroflot receives official notification from the aviation authorities of Ukraine that flights have been canceled will the company inform passengers and explain the rules on ticket reimbursement," it said in a statement.

The Ukrainian government statement also forbade Ukrainian state companies from using Russian software, particularly from the Russian anti-virus giant Kaspersky Lab.

Ukrainian state organizations were banned from using goods or services produced by sanctioned Russian companies. "The government is insisting on the immediate implementation of all sanctions defined by the decision of the Security Council," Yatseniuk said.

(Reporting by Pavel Polityuk; Additional reporting by Anastasia Lyrchikova in Moscow; Writing By Richard Balmforth and Alessandra Prentice; Editing by Mark Trevelyan)