The Red Cross says the humanitarian situation in Syria is now "catastrophic."
Pierre Kraehenbuehl, a top Red Cross official, said the organization was working with both sides in the conflict to ensure humanitarian aid gets through to people impacted by the nearly two-year-old conflict to unseat President Bashar al-Assad, which has left some 70,000 dead.
In Geneva, the UN World Food program said some 40,000 Syrians have fled the northeastern town of Shadadah. Rebels seized the town and most of a nearby oil field in days of clashes this week.
Meanwhile, on the ground inside Syria, rebels said they had seized a military airbase near the international airport in Aleppo.
Activists said government warplanes bombed areas around Aleppo's international airport earlier on February 15.
Quoted by AP, activists said some 150 people have died in fighting around the international airport in Aleppo in recent days.
Elsewhere, activists said regime tanks shelled the town of Khan Sheikhun in the province of Idlib, with at least 11 civilians reported killed.
Fighting was also reported in the outlying districts of Damascus, with government forces reportedly shelling the eastern district of Jobar where rebels have secured strongholds.
In Finland, the Customs Investigation Service said it had intercepted a shipment of spare parts for tanks en route to Syria from Russia.
The service's head, Petri Lounatmaa, said a shipment had been seized on January 8 because it lacked the proper paperwork plus 9.6 tons of tank parts.
The service suspects the shipment violated a European Union ban on weapons exports to Syria and is investigating with other international authorities.
On the diplomatic front, the opposition's main umbrella group, the Syrian National Coalition, said in a statement it would not allow Assad or members of his security services to participate in talks to end the crisis.
It did not rule out, however, dialogue with some members of his ruling Baath party, welcoming talks with "honorable people" from all parts of society who "have not been embroiled in the crimes against the Syrian people."
Still, neither side has proposed a concrete plan for talks.
In Turkey, Foreign Minister Ahmet Davutoglu proposed that the UN Security Council set up humanitarian zones that would be under joint government-opposition control to facilitate the delivery of aid to Syrian civilians.
With reporting by AP and Reuters