Fourteen crew have been kidnapped from a Chinese heavylift ship in the Gulf of Guinea, the latest in a spate of pirate attacks in the increasingly dangerous West African region.

The 48,127-dwt Liberia-flag Zhen Hua 7 (built 1998) was reported to have had some crew members unaccounted for after a boarding incident northwest of Sao Tome, Dryad Global had said in a note on Friday.

The security company later confirmed that 14 Chinese seafarers were abducted.

The vessel, understood to have had a crew of 27 personnel, was headed for Sao Tome escorted by the Italian naval frigate Federico Martinengo, Dryad said.

This is the 21st kidnapping incident in the Gulf of Guinea this year, with 95 crew members having been held captive before this.

Dryad added: "With the confirmation of the latest kidnapping there is a potential that the rate of incidents will decline in the short term.

"However, whilst it is not confirmed that the activity over the past 9 days was perpetuated by a single [pirate group], the risk profile for all vessels operating within the region remains at critical, with attacks assessed as highly likely/expected daily."

According to shipping databases, the vessel is managed by Shanghai Zhenhua Shipping, which shares an address with its registered owner, Zhen Hua 7 Shipping. TradeWinds has approached Shanghai Zhenhua Shipping for comment.

The attack is the eighth in nine days in the region, which has in recent years become a piracy hotspot.

This week, three other ships were attacked, all in Benin, but no seafarers were kidnapped.

On Monday, the 73,700-dwt tanker La Boheme (built 2007) was approached by two skiffs, 95 nautical miles (176 km) south of Cotonou, but backed off after the crew mustered in the citadel and the ship executed evasive manoeuvres.

On Wednesday, the 13,100-dwt chemical carrier Valley Oak and 52,000-dwt MR tanker Jane (both built 2008) were attacked off Cotonou. In both cases, the attacks were aborted.

Dryad and fellow security group Ambrey described the situation in the Gulf of Guinea as "critical" after attacks last week.

Ambrey, warning that using the ship's citadel might not be enough, recommended shipowners hire local armed guards and arrange security vessel escorts.

Dryad warned that the more attacks failed, the more desperate pirate groups may become due to counter-piracy activity and logistical strain.