A new report on piracy says the number of ships targeted by Somali pirates has dropped to its lowest level since 2009, while hijackings have spread in the Gulf of Guinea.

The report Monday from the International Maritime Bureau said Somali pirates carried out 70 attacks in the first nine months of this year, down from 199 in the same period the year before.

It said just one ship reported an attempted Somali pirate attack between July and September, compared to 36 reports in the same three months in 2011.

The shipping industry group said Somali pirates have been deterred by international navies policing the waters near the Horn of Africa and by ships using armed guards and adopting other onboard security measures.

The IMB report noted that piracy in the Gulf of Guinea is becoming “increasingly dangerous” with 34 incidents in the first nine months of this year, up from 30 in the corresponding period last year.

The group said pirates have pushed westward from Benin to Togo, hijacking ships to steal refined oil products that can be easily sold on the open market.

It said the pirates cover their tracks by damaging communications and navigation equipment onboard the targeted vessels.

IMB director Pottengal Mukundan welcomed what he called the successful robust targeting of pirates by international navies off Somalia, but he also said there can be “no room for complacency.” He said those waters remain “extremely high risk” and said the naval presence “must be maintained.”