At least 19 children were injured in the Rakhine state of Myanmar when the bombings hit an elementary school for which the army and the rebels refused to take responsibility.
Clashes between government troops and Buddhist rebels, who have been fighting for greater autonomy for the impoverished region, have intensified. since december 2018 shifting Tens of thousands of people.
The armed rebellion of the Arakan army has brought a new chaos to the region from where more than 730,000 majority Muslims Rohingya fled a brutal military repression in 2017.
On Thursday morning, artillery fire struck the school in the village of Khamwe Chaung in Buthidaung Township, Tun Aung Thein, a member of the local parliament, told the Reuters News Agency. He said he didn't know who was responsible.
"According to the health department, 19 students are injured and one is seriously injured," said the legislator.
A military spokesman calculated the number of wounded in 20 and blamed the rebels for the attack.
"We treated students medically at the nearby military post and sent five to the hospital," Brigadier General Zaw Min Tun told Reuters by telephone.
Master Thar Aye Maung, from Khamwe Village, told the AFP news agency how his school was beaten Thursday morning, wounding 21 students.
"One girl is seriously injured. Most of the others have wounds on their hands and legs."
He said that all the injured children were of Khami ethnicity, a Buddhist minority in a state with a complex mosaic of different ethnic and religious groups.
The fight came about three kilometers (two miles) away from the village, he added. "We thought the shells could not reach our school."
A spokesman for Arakan's army denied that his fighters were responsible and said they had no artillery, and blamed the government troops.
& # 39; Misery for many & # 39;
The British embassy in Myanmar issued a statement urging an end to the violence, which follows the restoration last week of an internet shutdown in the region.
"The increase in violence in Rakhine state in recent days is causing misery to many of the people who live there," said Dan Chugg, British ambassador to Myanmar.
"The bombing of a school on Myanmar Children's Day, after the recent death of women and children, highlights the impact this is having on innocent people."
The statement urged all parties to do everything possible to protect civilians and asked the government to lift the internet restrictions.
In September, the Internet blackout was suspended in four municipalities in Rakhine, including Buthidaung, and one in the neighboring state of Chin, while the peace talks sought to end the fighting.
Officials cited "security and public interest requirements,quot; for the restoration.