Russian Prime Minister Vladimir Putin on Monday said he was in favor of Russia and its western neighbor Belarus uniting into a single state, as in the days of the Soviet Union.

"This is possible and very desirable," said Putin, when asked at a pro-Kremlin youth camp on Russia's Lake Seliger if Russia and Belarus could merge into one entity.

Belarus has banned the radio broadcast of several popular Russian songs with dissident undertones amid protests against the regime of the President Alexander Lukashenko, sources said on Tuesday.

Over the past few weeks several songs -- including late Soviet-era dissident rock icon Viktor Tsoi's famous "We Are Waiting for Change" -- have disappeared from the airwaves of radio stations.

Belarus arrested almost 300 people in a massive nationwide crackdown on Independence Day protests against the regime of authoritarian President Alexander Lukashenko, a rights group said Monday.

The Vyasna rights group said that 200 people were arrested in the capital Minsk during Sunday's protests while another 80 were arrested in other parts of the country including the regional centers of Grodno, Gomel and Mogilev.

Authoritarian Belarus must free its political prisoners and take the road to democracy, U.S. Secretary of State Hillary Clinton said Friday during a visit to neighboring Lithuania.

"Together, we demand that Belarus release political prisoners and embark on the path of democratic reform," Clinton told reporters after meeting with Lithuania's President Dalia Grybauskaite.

Belarus has arrested two suspects over the attack on the Minsk metro that killed 12, including a man suspected of planting the bomb at the station, deputy prosecutor general Andrei Shved said Wednesday.

"The first investigative actions are being carried out on these two people with lawyers. The first confessions have been obtained," he said, quoted by the Interfax-Zapad news agency.

The death toll rose to 12 Tuesday after a blast described as an act of terror tore through a metro station in the Belarus capital near President Alexander Lukashenko's headquarters.

"As of 2:30 local time (23:30 GMT), the number of dead reached 12 people, six of whom have been identified," the country's KGB security service said in a statement, cited by the Interfax news agency.

A blast on Monday tore through a packed metro station near Belarus President Alexander Lukashenko's headquarters, killing eleven commuters and wounding nearly 100 in a suspected act of terror.

The explosion left clouds of suffocating smoke inside the capital Minsk's busiest metro station, whose exits lead to both the strongman president's main office and his residence as well as the country's powerful Security Council.