Fifteen more ceasefire monitors of a total advance team of 30 are expected to be in Syria by Monday and every effort is being made to deploy the full mission of up to 300 observers, the spokesman for international mediator Kofi Annan said on Friday.

'We expect the 30 will be on the ground by the end of April, on Monday,' Annan spokesman Ahmad Fawzi told Reuters in Geneva. 'There is no delay... It is a whole process,' he said. 'They are deploying at remarkable speed.'

Syrian activists have been dismayed at the pace of observer deployment. A senior UN official said this week it would take a month to put the first 100 monitors on the ground, though the world body is working to speed up the pace of deployment.  

Fawzi said that it takes time to contact member states and for them to agree to transfer troops from other UN peacekeeping missions in the region.

The United Nations Security Council first authorised an advance team of 30 and last Saturday it agreed to send up to 300 unarmed observers. Two of the original team are now stationed in Hama and have visited the site of the blast, Fawzi said. 

'It takes time to get authorisation from member states, to extract them (the observers), to equip them and put their gear and transport together,' he said. 'It doesn't happen overnight... We are working flat out.'

Syria's government and rebels have traded blame for a huge explosion which killed 16 people in Hama on Wednesday, as a two-week-old U.N.-backed ceasefire looked increasingly fragile.-Reuters