Syria crisis: UN chief Ban Ki-moon condemns attacks
The head of the UN, Ban Ki-moon, has condemned the Syrian government for fresh military assaults despite agreeing to a deal to end the violence.
Mr Ban said the 10 April ceasefire deadline was "not an excuse for continued killing" by forces loyal to President Bashar al-Assad.
Activists say at least 100 people have been killed over the past two days as troops intensified operations.
Earlier, Turkey said it may need UN help after a surge in refugee arrivals.
After speaking to Mr Ban, Foreign Minister Ahmet Davutoglu said the rate of refugees had doubled since Mr Assad agreed to implementing the UN-Arab League plan.
The six-point peace plan, mediated by envoy and former UN chief Kofi Annan, envisages cessation of armed violence by all parties from 10 April, with a full ceasefire on 12 April.