*The clash took place over a Facebook post from a hacked account
*Four killed in the clash, dozens including police injured.
*BGB deployed to avert further untoward situation.
Four people were killed and an unspecified number of others injured in a clash between police and local people while demonstrating in Borhanuddin upazila on Sunday, demanding the punishment of a youth 'for a Facebook post' hurting the religious sentiment.
Four people -- Mizan, Mahfuz Patwari, Shaheen and Mahbub Patwari -- were killed, said Dr Abul Kalam Azad, medical officer of Bhola Sadar Hospital.
Thirty people who suffered bullet wounds during the clash were admitted to Barishal Sher-e-Bangla Medical College Hospital, said Dr Abul Hasnat Russell at the hospital's emergency department.
All of them were admitted to the hospital between 1:30 pm and 5 pm, he added.
Talking to local journalists, Sarkar Mohammad Kaisar, Superintendent of Bhola Police, said local people turned furious over the offensive remarks about Prophet Muhammad from the Facebook ID of Biplab Chandra Shuvo, a local man.
"The clash took place centering the hacking of a Facebook ID on October 18. We detained all those involved in ID hacking. They're now in custody. We sat in a meeting with local influential people, public representatives, imams and Alem who had assured us that they wouldn't hold their scheduled protest program today," he said.
But, today they started taking preparations to hold the program and then police appeared at the scene, the SP said.
"When we're leaving the place after the rally, some people started throwing brick chips at us forcing us to take shelter in an adjoining building and fire blank shots," the SP said.
Three people were killed and a policeman suffered bullet wounds during the clash, he said.
Md Enamul Haque, officer-in-charge of Borhanuddin Police Station, said Biplob on Saturday came to the police station to file a general diary claiming that his Facebook account was hacked.
"Biplob also said someone demanded extortion from him over mobile phone," he said.
Meanwhile, one platoon of BGB troops was sent to the spot in helicopters while another three platoons were sent by road to quell the situation," said MdShariful Islam, public relations officer at the Border Guard Bangladesh (BGB) headquarters.
Besides, one platoon of Bangladesh Coast Guard have been deployed on the spot, said Lt Hayat-Ibne-Siddique, media officer of Coast Guard headquarters.