The U.S. House of Representatives has approved a bill to support democracy and human rights in Belarus, where police have arrested hundreds of people demonstrating against authoritarian President Alexander Lukashenko.

The Belarus Democracy and Human Rights Act of 2011 calls for the release of all political prisoners in Belarus, including those detained in the crackdown following Mr. Lukashenko's disputed reelection in December.

The bill refuses to recognize the results of the December elections, calling them “fraudulent.” It also offers congressional support for U.S. restrictions on senior Belarusian officials and their family members and business partners, as well as members of the security services involved in the post-election crackdown.

House lawmakers passed the bill late Wednesday, and it now goes to the Senate.

The bill's author, Republican Representative Chris Smith, said the measure states a U.S. government policy of strong support for the Belarusian people in their struggle against what he described as Mr. Lukashenko's “dictatorship.” He said it “encourages those struggling for decency and basic rights.”

On Wednesday, Belarusian police arrested more than 400 people during another day of anti-government protests.

Marches were held Wednesday in most major cities, including Grodno, where witnesses say police grabbed people by their hair and clothes and threw them into vans. Women and children were among those arrested.

Several journalists were also arrested after police warned them not to turn on their cameras.

Opposition has grown against Mr. Lukashenko's 17-year rule and the country's worsening economic crisis.

The opposition has used the Internet and social networks to organize a wave of marches against the government.

Western governments have decried President Lukashenko's crackdown on protesters, saying he has shown a disregard for democratic values. The United States has called Mr. Lukashenko Europe's last dictator for suppressing free speech and human rights and rigging elections. Washington and the European Union have imposed numerous sanctions against his government.

Belarus is also facing economic turmoil with its national currency plunging in value.