The Sri Lankan president on Tuesday vowed a major shakeup to the nation’s security agencies that ignored warnings ahead of the deadly Easter Sunday terror attacks — as reports emerged that officials had been tipped off to the bombings “hours before” they happened.

The announcement from President Maithripala Sirisena comes two days after terrorists killed at least 321 people in a series of suicide bombings at churches and hotels that rocked the country, and claimed at least four American lives.

“I will completely restructure the police and security forces in the coming weeks. I expect to change the heads of defense establishments within the next 24 hours,” Sirisena said a televised address to the nation.

Sri Lankan intelligence officials received multiple warnings about planned terror attacks on the South Asian nation — including one from Indian intelligence counterparts just “hours before” the first explosion, Indian and Sri Lankan sources revealed Tuesday.

Sirisena said those warnings never made it up the chain.

“The security officials who got the intelligence report from a foreign nation did not share it with me. Appropriate actions would have been taken. I have decided to take stern action against these officials,” he said.

ISIS, the Islamic terrorist group thought to be diminished in the Middle East, claimed responsibility for the attacks on Tuesday. An image of three men said to be among the suicide bombers with a flag of the terror group in the backdrop also emerged on Tuesday.

With Post wires