European leaders are to triple funding for rescue operations aimed at migrant boats in the Mediterranean following crisis talks in Brussels.

The EU will also look at ways to capture and destroy smugglers' boats and deploy immigration officers to non-EU countries, officials said. Several EU member states have promised more ships and other resources. The summit comes after more than 750 people died on a boat crossing from Libya on Sunday.

Earlier, funerals for 24 of the victims were held in Malta. The number of people fleeing war and poverty in the Middle East and Africa has risen sharply in recent months.

More than 35,000 are thought to have crossed from Africa to Europe this year and some 1,750 have died while attempting the journey. The estimated toll from Sunday's capsizing was the worst on record.

The boost in funding to some €120m (£86m) brings spending back up to about the level of Mare Nostrum, an Italian-run search-and-rescue operation that was cancelled last year.

Several member states pledged additional naval resources on Thursday. The UK - in the past a leading advocate of reducing naval patrols - said it would contribute helicopter carrier HMS Bulwark, two patrol boats and three helicopters. Germany, France and Belgium also offered ships.

Analysis: Chris Morris, BBC News, Brussels Human rights groups are already criticising the summit for failing to expand the operational area of EU-led naval patrols, which could have taken them closer to the Libyan coast. Unless the ships are in the right place, they argue, migrants will continue to drown.

And even if naval operations manage to rescue the vast majority, there are bitter disputes about how to deal with the tens of thousands who make it to safety. Britain for example has said it will provide significant naval support, but it won't accept more asylum seekers.

Some people in southern Europe say that's not enough. The burden has to be more equitably shared. But there is no common asylum and immigration policy within the EU. Different countries have very different priorities. It will take years to get the balance right. This summit is only the start.

A "something must be done" moment

European Council President Donald Tusk said leaders had asked EU foreign affairs chief Federica Mogherini "to propose actions in order to capture and destroy the smugglers' vessels before they can be used". German Chancellor Angela Merkel said any kind of military action could only be based on international law.

"There are two possibilities: either a UN Security Council Resolution or a unity government in Libya. We have neither at the moment," she said. Italian Prime Minister Matteo Renzi said the UK and France had "committed to get a resolution from the United Nations for an intervention in Libya".

Mr Tusk added that the EU would also "step up co-operation against smuggling networks by working through Europol and by deploying immigration officers to third countries" and would "co-ordinate the resettlement of more people to Europe on a voluntary basis and with an option for emergency relocation". Last year, some EU members had said Mare Nostrum was too expensive and expressed concerns that it was encouraging more migrants.

But its replacement by the more limited Triton operation was widely criticised by activists. Human rights group Amnesty International said the decision had "contributed to a dramatic increase in migrant and refugee deaths".

What major EU players say Italy wants the EU to double resources for maritime and border controls, a system for processing migrants on the ground in Africa, a fairer distribution of genuine refugees within the EU and military action against the traffickers in the Mediterranean, similar to the anti-piracy operation in the Horn of Africa.

Greece has proposed a plan to improve existing search-and-rescue operations, sharing the burden of settling the refugees more equally among EU countries, and it wants the EU to take a more active role in conflict resolution in Syria, Libya and Iraq.

France wants to focus on controlling migration flows - President Francois Hollande says the emphasis should be on disrupting people traffickers Germany also says that the problem needs to be treated at the source; it is noncommittal about whether rescue measures should be boosted, fearing it could encourage trafficking.

Sweden - which has previously sent surveillance ships and planes to the Mediterranean to look out for migrant ships, says it is prepared to do so again.

Is military force the solution? Deadly migrant routes explained

The UN had also criticised an EU 10-point action plan from earlier this week as "minimalist". And after Thursday's summit, former Italian foreign minister Emma Bonino said she was "really disappointed". "It's a wasted opportunity with a lot of fanfare, but no concrete result," she told the BBC.

Ms Merkel said money should be no object: "If it turns out that the funds are not sufficient we will have to talk about it again." French President Francois Hollande said it was "a question of fixing yesterday's errors."