Nearly three months after Israeli forces arrested Khader Adnan, the senior Palestinian Islamic Jihad operative has died in prison, following an 87-day hunger strike.

Reuters cited Israeli prison authorities, who said Adnan, 45, “refused to undergo medical tests and receive medical treatment” and “was found unconscious in his cell” early Tuesday morning.

The WAED Prisoners Association in Gaza told Reuters that “Khader Adnan has been executed in cold blood.”

Around 6:30 a.m. local time, sirens sounded in southern Israel.

“Three rockets were launched from Gaza toward Israeli territory. No interceptors were launched in accordance with policy,” the Israel Defense Forces tweeted.