On the fifth day of the second impeachment trial of former President Donald Trump, the Senate voted to allow witnesses called US media.
A total of 55 Senators voted in favor of questioning of witnesses, while 45 were against.
Five GOP Senators supported the decision.
Two-third of the Senate votes is required for impeachment. It means that 17 former Republicans should vote against the former president.
Trump is accused of supporting the mob on January 6, when they rushed into the Capitol building. The Senate is to define how far Trump is guilty.