Operators using a newly installed system may have wrongly signaled two trains that crashed head-on, killing at least 110 people and injuring 1,000 in the country's worst rail accident, authorities said.

About 40 people remained in critical condition Monday, according to one hospital official, who spoke on condition of anonymity.The 10-car express train and seven-car mail train slammed into each other Sunday outside the farming village of Maizdi Khan, sending cars tumbling and tossing passengers into freshly harvested rice paddies.

The express train was traveling at about 50 mph, the mail train coming to a halt, authorities said.

Communications Secretary Mazurul Karim estimated that more than 2,000 people were aboard the trains, many of them Moslem pilgrims. He said, however, that people routinely ride between the cars and on the roofs, making a precise count difficult.

The government appointed a commission to investigate the collision and ordered that the panel's findings be ready within two weeks. It declared Monday a day of mourning.

Shortly after the accident, senior officials of the state-run railroad said they suspected operators may not have known how to properly work a sophisticated digital signaling system installed five days earlier.

"Human failure and wrong signaling may have caused the two trains to come on the same track, leading to the collision," said one official, who spoke on condition of anonymity.

But Communications Minister Anwar Hossain disputed their suspicions, saying more than 200 trains had traveled on the track since the system was installed Tuesday. The track on which the crash occurred share north- and southbound traffic, so trains often must wait on sidings for trains going in the opposite direction to pass.

Rescue workers using two large cranes to pull apart the crumbled wreckage finished the search for victims early Monday and reopened the track. Karim said no bodies were found inside.

Soldiers, fire officials and villagers pulled at least 100 bodies from the trains on Sunday, and another 10 people died at hospitals, police and railway officials said.

At the scene, sobbing relatives tried to look for loved ones among rows of bodies laid alongside the single track, but were held back by police.

"Oh, God! Bring brother back!" cried Sunil Daniel, pressing his arms against his chest.

Hundreds of injured were taken to hospitals at Tongi, five miles to the north, and to the capital, Dhaka, 22 miles to the south.

The government offered $3,125 as compensation to relatives of the dead and $2,560 to each of the injured.

The express train was headed north from Dhaka to Tongi, then southeast to Chittagong. The mail train, bound for Dhaka, had just stopped in Tongi.

Officials said many involved in the crash were pilgrims traveling to Tongi, where hundreds of thousands of Moslems have gathered for Biswa Ejtema, or World Congregation, Islam's largest gathering after the Haj in Mecca.

Many involved in the crash were pilgrims traveling to Tongi, where hundreds of thousands of Moslems have gathered for Biswa Ejtema, or world congregation, Islam's second largest pilgrimage after the Haj in Mecca, Saudi Arabia.

"It was a big jolt and minutes later I found myself trapped inside a tilted coach," said Kohinoor Begum, 40, as she waited for treatment at Dhaka's Pangu Hospital for cuts.

Prior to Sunday, the worst train crash in Bangladesh occurred on Jan. 26, 1981, near northern Chuadanga, and killed at least 75 people.

According to government statistics, at least 2,537 train accidents have occurred in Bangladesh in the past 15 years, killing at least 883 people and injuring more than 7,000.