Russia launched new missile strikes on the Odesa region raising fresh doubts about plans to restart grain shipments from Ukrainian ports this week.

The UN insisted plan on re-opening three ports were going ahead despite missile strikes at the weekend but the statement was followed by a further attack early on Tuesday.

The US said it was exploring other options to bring 20m tonnes of grain stored ready for export but admitted that shipments from Baltic Sea ports remained the best option to prevent a global food crisis.