BOSTON — Climate change protesters dropped their pants at the Massachusetts Statehouse during a debate on a proposed tax relief package Thursday to bring attention to what they say is the need for swifter action against the use of fossil fuels.

About 1 p.m., protesters stood, turned their backs to the Senate chamber and lowered their pants to reveal letters that spelled out STOP PASSING GAS! on their bare backsides.

The protesters were all wearing pink thongs.

The eight protesters were chanting and disrupting the Senate session, according to state police investigators. Just before 2 p.m., the protesters were told that the public gallery was closed.

After being warned that they were subject to arrest, the protesters refused to leave and were placed under arrest and escorted out of the chamber, investigators said. They were charged with trespassing on state property, disorderly conduct and indecent exposure.

The senators then returned and continued their debate.

The group Extinction Rebellion has staged other protests at the Statehouse. They say they plan to continue their efforts until lawmakers approve legislation banning new fossil fuel infrastructure.

Former Gov. Charlie Baker last year signed a major climate bill meant to bring the state closer to its goal of net-zero greenhouse gas emissions by 2050.

The new law encourages the development of offshore wind and solar energy and gives some local authority to limiting the use of fossil fuels in building projects.

The eight protesters were chanting and disrupting the Senate session, according to state police investigators. Just before 2 p.m. the group was told that the public gallery was closed.

After being warned that they were subject to arrest, the protesters refused to leave and were placed under arrest, investigators said. They were charged with trespassing on state property, disorderly conduct, and indecent exposure.