Explosives were used to blast boulders that were hampering the ongoing restoration work on the 270-km-long Jammu-Srinagar national highway, which remained closed due to multiple landslides triggered by incessant rains for the third consecutive day on Thursday, officials said. With the improvement in the weather, the restoration work at over half-a-dozen places in Udhampur and Ramban districts was speeded up in the morning as over 700 Kashmir-bound stranded vehicles, mostly trucks carrying essential commodities, were cleared, the officials said.