Thiruvananthapuram, Jul 15 (IANS): In a bizarre incident that happened near Kollam, about 70 kms from the state capital, four casual workers, on Thursday who had come to clean a 100 feet well, died due to suspected presence of poisonous gas.

The dead included Somarajan, 53, Rajan, 36, Manoj, 32, and Sivaprasad, 24.

According to an eyewitness, the incident happened around 10 a.m. when two workers, part of the four-member group who came to clean a 100 feet deep well, decided to go into the well.

"After a while hearing no response from the two who had entered the well, a third person decided to go into the well and the fourth person also went after him. Fearing that things were not right, anxious villagers called the Fire Force," said the eyewitness.

Soon the team of Fire Force and Police arrived and started their rescue operations and all the four were taken out and moved to the hospital.

After arriving at the hospital, all the four died.

A Fire Force official who took part in the rescue operation felt uneasy and was taken to the hospital and is under treatment.