AMITE, La. (AP) — Four inmates escaped a south Louisiana jail over the weekend and two were still missing Tuesday, authorities said.

Authorities were unaware that four inmates had escaped until a phone call tipped them off, the Tangipahoa Parish Sheriff’s Office said Monday.

The inmates escaped in pairs — the first on Saturday afternoon and the second on Sunday, said Deputy Chief Jimmy Travis at a news conference, WVUE-TV reported. Travis said all four broke through a corroded piece of chain-link fence, crawled under an 8-inch (20-centimeter) gap in a wall, and scaled two razor-wire fences.

Jail authorities learned of two of the escapes Sunday afternoon when a tipster reported seeing two of the inmates at a relative’s house looking for a place to stay.

When deputies began investigating, they found the other two also were missing.

“It’s very concerning. If the proper headcounts had been conducted, we would have known about it immediately,” Travis said. “It’s a failure. We had a failure within.”