Dhaka, Sept. 29 -- Four attacks in just three days involving land disputes, land grabs, vandalism, and looting have brought a troubling new pattern into focus in Dhaka.

In some cases, dozens of people joined the attacks. In others, the numbers ran into the hundreds. Heavy machinery was even used in at least one incident to raze structures to the ground.

Land grabbing, the occupation of pavements and vacant plots, obstruction of construction work, and extortion are hardly new to the capital.

What is igniting fresh concern is the way some of the latest incidents have unfolded -- groups arriving together, forcing their way onto properties, vandalising structures, and removing valuables.

Some journalists and others who have followed crime...