Malta "abandoned" a dinghy with up to 200 migrants on board and redirected them to Italy, Matteo Salvini charged on Saturday, sparking another spat between the two countries.

In social media posts, Italy's deputy prime minister claimed a Maltese rescue boat  had abandoned a raft carrying 150 to 200 migrants in the middle of the Mediterranean.

"Valletta had assumed the coordination of rescue operations, but as usual it is trying to redirect the migrants to our country. It is yet again a shame, worthy of this incapable and harmful European Union," he wrote. 

In a reference to the budget dispute, Mr Salvini accused Brussels of being too busy "writing letters" to Italy to bother dealing with the problem of migration. 

The Maltese government has not yet reacted to the right-wing leader's latest broadside. The condition of those on board is not known. 

Mr Salvini has repeatedly attacked Malta for shirking its responsibility where it comes to migration. The Maltese government has often cited migrants' right of passage and that its Armed Forces cannot intervene at sea provided they are not facing an emergency. 

Read: 'If Malta and France treat us like fools, they will face the consequences' - Salvini

On November 10, the Maltese authorities gave fuel and a compass to migrants to help them reach Lampedusa, prompting a war of words between the two governments. 

Home Affairs Minister Michael Farrugia had insisted Malta had gone beyond its international obligations, reminding Mr Salvini that Malta had allowed migrants rescued at sea to disembark in Malta after Italy had shut its ports to them.

The two countries' clampdown on migrant rescue vessels has elicited criticism by humanitarian organisations.