Brussels - European Union warships will be allowed to shoot at pirates caught hijacking commercial vessels off the coast of Somalia, EU foreign policy chief Javier Solana said Monday.

Solana was speaking after EU foreign ministers in Brussels formally endorsed the bloc's "Atalanta" mission, which starts Tuesday.

The foreign policy chief called the mission's rules of engagement "very robust", saying it will enjoy "all the necessary measures needed to fulfill its mandate." Asked whether such rules include the possibility of shooting at pirates caught in the act, Solana said "hopefully, this will not be necessary."

A Danish warship operating in the Gulf of Aden last week ended up rescuing seven suspect pirates, rather than arresting them, after its speedboat was found drifting with a malfunctioning engine.

Danish officials seized weapons but said they could not apprehend the suspects since they could not be certain of their intentions. They were eventually handed over to Yemeni officials.

The case has helped highlight the legal difficulties involved in cracking down on pirates, who often operate in international waters.

The EU mission, consisting of six warships and three maritime reconnaissance aircraft, will be tasked with escorting merchant ships and World Food Programme vessels delivering food aid to Africa.

Scheduled to last for one year at a cost of 8.3 million euros (10.7 million dollars), it will flank a similar NATO mission, whose mandate expires later this month.

According to the International Maritime Bureau (IMB), there have been almost 100 attempts at piracy in the region this year, with around 40 of them successful.

One of the most prominent hijacking involved the Sirius Star supertanker, which was carrying 100 million dollars worth of crude oil when it was taken. Negotiations on a multi-million-dollar ransom are still underway. (dpa)