The U.S. Supreme Court early Tuesday denied Arkansas’ request to lift a stay that would have allowed the state to carry out its first execution in 12 years. Eight inmates were scheduled to be executed before April 30, when one of the three drugs in a combination used for lethal injection expires.

Bruce Ward and Don Davis — two of the death row inmates — were scheduled to be put to death Monday night. The next two executions are scheduled for Thursday night.

Attorney General Leslie Rutledge stated that there are five upcoming executions "with nothing preventing them from occurring."

Capital punishment has been a hot debate topic in the U.S. with several people opposing death penalty. Limited availability of the required drugs has also proved to be a hindrance for states to carry out executions.

Check out the list of states that have death penalty and the methods used for execution.

Alabama: Lethal injection or electrocution

Arizona: Lethal injection or gas. However, if convicted for a crime committed prior to Nov. 23, 1992, the inmate may choose between lethal injection and gas inhalation.

Arkansas:  Lethal injection or electrocution

California: Lethal injection or gas.

Colorado: Lethal injection

Florida: Lethal injection or electrocution

Georgia: Lethal injection

Idaho: Lethal injection

Indiana: Lethal injection

Kansas: Lethal injection.

Kentucky: Lethal injection is the only method. However, inmates who committed crimes before 1998 may select lethal injection or electrocution.

Louisiana: Lethal injection

Mississippi: Lethal injection

Missouri: Lethal injection or gas

Montana: Lethal injection

Nebraska: Lethal injection

Nevada: Lethal injection

New Hampshire: Lethal injection or hanging

North Carolina: Lethal injection

Ohio: Lethal injection

Oklahoma: The state allows nitrogen gas use if lethal injection is considered unconstitutional or "otherwise unavailable." If nitrogen gas and lethal injection are both deemed unconstitutional or "otherwise unavailable," electrocution method is used. If all these methods are held unconstitutional or "otherwise unavailable," firing squad is used to put an inmate to death.

Oregon: Lethal injection

Pennsylvania: Lethal injection

South Carolina: Lethal injection or electrocution

South Dakota: Lethal injection

Tennessee: Lethal injection for inmates who committed capital offense after Dec. 31, 1998. However, those who committed the offense before that date are allowed to choose electrocution by written waiver.

Texas: Lethal injection

Utah: Lethal injection or firing squad

Virginia: Lethal injection or electrocution

Washington: Lethal injection or hanging

Wyoming: Lethal injection or gas