Law enforcement officials are continuing to negotiate with at least one hostage-taker for the release of two children and two adults he is still holding inside a house in the southern Chicago suburb of Harvey.

The standoff began at 12:45 p.m. Tuesday when Harvey police responded to reports from a neighbor of a possible burglary at the home. Two officers were wounded in an initial exchange of gunfire.

Four children were released after hours of talks.

In an update Wednesday morning, Cook County Sheriff Tom Dart said negotiations have been going on ``literally all night'' and that the hostage-taker and a possible second suspect have been assured that they will not be hurt if they cooperate.

He says the four remaining hostages appear to be unharmed.