DAMASCUS, Jan. 21 (Xinhua) -- A fragile ceasefire between the Syrian interim government and the Kurdish-led Syrian Democratic Forces (SDF) came under strain on Wednesday, as both sides accused each other of violations that resulted in casualties.

Syria's defense authority said SDF forces carried out more than 35 attacks on army positions during the first day of the four-day ceasefire, killing 11 soldiers and wounding more than 25 others.

The ceasefire, which began on Tuesday, was announced by the interim government as part of confidence-building efforts following recent agreements with the SDF aimed at de-escalating tensions and restoring stability in northern and eastern Syria.

In a counterstatement, the SDF accused what it described as "Damascus factions" of breaching the truce in multiple locations across the Jazira region and around Kobani.

According to the SDF, artillery shelling and ground attacks were reported in areas including Zarkan in northern Hasakah, Tal Baroud south of Hasakah, and villages near the town of Sarrin.

The SDF said its forces repelled several assaults and reported the death of a woman in shelling on a village south of Kobani, calling on international guarantors to intervene to protect civilians and preserve stability.

Earlier in the day, Syrian interior authority and the army warned civilians to stay away from former SDF positions in Raqqa, Deir al-Zour, eastern Aleppo and Hasakah provinces.

State news agency SANA reported that SDF and PKK-linked elements had planted explosives in tunnels, buildings, homes, vehicles and mosques, including booby-trapped furniture and disguised explosive devices. The authorities said these explosives had already caused civilian and military casualties, urging residents to report any suspicious objects immediately.

The interior authority also declared the Al-Hol camp and newly secured detention facilities as prohibited security zones, saying forces were working to secure the sites, track down remaining IS fugitives and complete data collection to stabilize the situation. Recent fighting around detention facilities holding IS suspects and their families has heightened fears of security breaches and further displacement.

The developments unfolded against the backdrop of broader regional concerns over IS detainees. On Wednesday, U.S. Central Command announced the launch of a mission to transfer IS detainees from northeastern Syria to Iraq, confirming that 150 IS fighters had already been moved from a facility in Hasakah to a secure location in Iraq.

U.S. officials said up to 7,000 detainees could ultimately be transferred, citing the need to prevent potential breakouts and mitigate regional security risks.

The renewed violence and competing claims underscore the fragility of the ceasefire and the deep mistrust between the Syrian interim government and the SDF, despite recent agreements on troop withdrawals, security arrangements and the gradual return of state authority.