Kuwaiti authorities say the alleged leader of a terrorist group has died after suffering a heart attack while in custody.

Officials said Amer Al-Enezi died late Tuesday.

He was captured when Kuwaiti security forces stormed a suspected terrorist hideout near Kuwait City about two weeks ago. Four Islamic militants were killed and three others were captured during the January 31 raid.

Officials described the alleged ringleader as a former mosque preacher and a reputed al-Qaida figure.

Kuwaiti security forces have recently stepped up efforts to combat Islamic militants in the emirate who are plotting to attack U.S. troops and other Westerners. Kuwait is a staging area for American forces in Iraq.