Kyrgyzstan has said it agreed to a ceasefire with Tajikistan after the heaviest clashes in years erupted along the neighbouring countries’ disputed frontier.

In a statement on Thursday, Kyrgyzstan’s foreign ministry said a “complete ceasefire” had been agreed from 8pm local time (14:00 GMT), with military forces returning to bases. Tajikistan did not immediately release an official statement on the agreement.

The two countries have long been locked in border disputes, including sporadic clashes along the frontier. More than a third of the border is disputed, with the area surrounding the de facto Tajik enclave of Vorukh, where Thursday’s conflict erupted, a regular flashpoint over territorial claims and access to water.

But the latest outbreak of fighting involving their two militaries was rare and raised fears of escalating into a wider conflict.

Earlier in the day, both sides said their forces had clashed, with Kyrgyzstan saying its troops had seized a border post. Its health ministry said in a statement late on Thursday that the country had suffered 46 casualties, including one death, during the fighting.

Tajikistan made fewer statements as fighting raged. Its national security committee said earlier on Thursday that two people had been admitted to hospital with gunshot wounds, one of whom was in a serious condition.

The Russian state news agency RIA Novosti reported that as many as three Tajik citizens had died in the conflict, with 31 wounded, citing a source in the municipal administration of the Tajik town Isfara.

The clashes followed a reported conflict over water infrastructure at the frontier between the two, which both gained independence after the collapse of the Soviet Union in 1991.

The conflict allegedly started after Tajik authorities installed a surveillance camera on a Kyrgyz water station at the border.

Local communities from both sides then started throwing rocks at each other and exchanged gunfire, with the militaries from both sides also involved in the conflict.

Tajikistan’s security committee accused Kyrgyz servicemen of opening fire on Tajik troops “at the site of the main water distribution point, located in the upper reaches of the Isfara River”.

It said Kyrgyz and Tajik civilians had on Wednesday become embroiled in a conflict over river infrastructure.

The foreign ministry of Uzbekistan, the most populous country in the region and a neighbour of both countries, had earlier called for the “immediate cessation of hostilities” and offered to assist in resolving the crisis.

Russian foreign ministry spokeswoman Maria Zakharova told reporters that Moscow was monitoring the conflict.

The International Red Cross and Red Crescent Movement said it had assisted in evacuating more than 600 people from a village at the border to the region’s administrative centre Batken.

Images released by the group showed children sheltering in temporary accommodation.

Border disagreements between the three countries that share the fertile Fergana Valley – Kyrgyzstan, Tajikistan and Uzbekistan – have their roots in border demarcations during the Soviet Union.

The twisting frontiers left several communities with restricted access to their home countries.