Opposition lawmakers crowd around Masahisa Sato (2nd L), deputation chairman of the upper house special committee on security, at an upper house special committee session on security-related legislation at the parliament in Tokyo, Japan, September 17, 2015. [Photo/Agencies]

TOKYO - Japan's upper house committee on Thursday approved legislation for a security policy shift that would allow troops to fight abroad for the first time since World War II, a ruling party lawmaker said.

Opposition lawmakers tried to physically prevent the vote in a chaotic scene carried live on national television. The legislation has sparked huge protests from ordinary voters.

Opponents say the revisions, which the government aims to get voted into law by the entire upper house this week, violate the pacifist constitution and could embroil Japan in US-led conflicts around the globe.

Prime Minister Shinzo Abe's ruling bloc has an upper house majority, but opposition parties have vowed to prevent a vote by the full chamber before parliament disperses on Sept 27, even if they have to use delaying tactics such as no-confidence and censure motions. The legislation has already been approved by the lower house.