Lt. Col S.M. Ariful Islam, commanding officer of the Bangladesh border guard in Teknaf, said on Friday he was aware of at least three Rohingya injured in explosions.

Bangladeshi officials and Amnesty researchers believe new explosives have been recently planted, including one that the rights group said blew off a Bangladeshi farmer's leg and another that wounded a Rohingya man. Both incidents occurred Sunday. It said at least three people including two children were injured in the past week.

“It may not be land mines, but I know there have been isolated cases of Myanmar soldiers planting explosives three to four days ago,” Ariful said Friday.

Myanmar Presidential spokesman Zaw Htay did not answer phone calls seeking comment Sunday. Military spokesman Myat Min Oo said he couldn't comment without talking to his superiors. A major at the Border Guard Police headquarters in northern Maungdaw near the Bangladesh border also refused to comment.

Amnesty said that based on interviews with eyewitnesses and analysis by its own weapons experts, it believes there is “targeted use of landlines” along a narrow stretch of the north-western border of Rakhine state that is a crossing point for fleeing Rohingya.

“All indications point to the Myanmar security forces deliberately targeting locations that Rohingya refugees use as crossing points,” Amnesty official Tirana Hassan said in a statement Sunday. “This a cruel and callous way of adding to the misery of people fleeing a systematic campaign of persecution.”

The violence and exodus began on Aug. 25 when Rohingya insurgents attacked Myanmar police and paramilitary posts in what they said was an effort to protect their ethnic minority from persecution by security forces in the majority Buddhist country.

In response, the military unleashed what it called “clearance operations” to root out the insurgents. Accounts from refugees show the Myanmar military is also targeting civilians with shootings and wholesale burning of Rohingya villages in an apparent attempt to purge Rakhine state of Muslims.

Bloody anti-Muslim rioting that erupted in 2012 in Rakhine state forced more than 100,000 Rohingya into displacement camps in Bangladesh, where many still live today.

Rohingya have faced decades of discrimination and persecution in Myanmar and are denied citizenship despite centuries-olds roots in the Rakhine region. Myanmar denies Rohingya exist as an ethnic group and says those living in Rakhine are illegal migrants from Bangladesh. (AP)