NEW DELHI / ISLAMABAD - Loud blasts were heard in Indian-controlled Kashmir on Saturday evening, just three hours after India and Pakistan agreed to observe a ceasefire and end military actions, officials said.

The massive blasts were audible in Srinagar city, the summer capital of Indian-controlled Kashmir.

According to the region's Chief Minister Omar Abdullah, explosions were heard across Srinagar. "This is no ceasefire. The air defense units in the middle of Srinagar just opened up."

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It was reported that in Akhnoor, Rajouri, and R S Pura sections, the two sides exchanged heavy shelling and artillery. The exchange of fire was also reported along the Line of Control (LoC) in Palanwalla section of Jammu.

Immediately after the blasts, a blackout was enforced.

Punjab

Also on Saturday, at least four civilians were injured on Saturday in two separate incidents of unprovoked ceasefire violations by Indian forces in Pakistan's eastern Punjab province, official sources told Xinhua.

The violations took place along the Working Boundary in Sialkot district, which separates Pakistan's Punjab province from the Indian-controlled Kashmir, according to the sources who spoke on condition of anonymity.

In the first incident, at around 6:00 pm local time, an 18-year-old girl sustained a back injury in Pasrur area of Sialkot.

A second incident occurred when Indian forces opened fire between 6:23 pm and 6:30 pm local time in Harpal section, targeting civilian settlements.

"Three members of a local family from Jangal village were also injured in unprovoked firing from the Indian side," the sources added.

Ceasefire violations were also reported in Kotli, Bhimber, Chamb, and Keran sections along the Line of Control dividing Kashmir, the sources said.

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Earlier in the evening, security sources reported multiple incoming suicide drones from the Indian side, targeting Pakistani cities between 7:00 pm and 9:00 pm local time. The drones were detected and intercepted, the sources added.

Tensions between the two neighbors had appeared to ease earlier in the day after both sides announced a ceasefire agreement. However, the latest violations have raised fresh concerns about the fragility of peace efforts in the region.

Earlier in the day, Pakistan and India announced that they had agreed on a ceasefire.

The announcement came following four days of military strikes on each other.

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On Wednesday, India launched airstrikes on Pakistani targets to avenge last month's killing of 26 people by gunmen in Pahalgam town, about 89 km east of Srinagar, the summer capital of Indian-controlled Kashmir.

India blamed Pakistan for being behind the incident, a charge denied by Pakistan.

The situation along the LoC dividing Kashmir had been tense as troops of India and Pakistan deployed on both sides of the ceasefire line were engaged in an exchange of fire and artillery.

Meanwhile, UN Secretary-General Antonio Guterres on Saturday welcomed the ceasefire agreement between India and Pakistan.

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"The Secretary-General welcomes the ceasefire agreement between India and Pakistan as a positive step toward ending current hostilities and easing tensions," Stephane Dujarric, spokesman for the UN chief, said in a statement.

"He hopes the agreement will contribute to lasting peace and foster an environment conducive to addressing broader, longstanding issues between the two countries," Dujarric said.

The spokesman added that the United Nations stands ready to support efforts aimed at promoting peace and stability in the region.

Pakistan and India announced earlier Saturday a ceasefire with immediate effect, following days of military strikes on each other.