This was followed by a string of attacks against Western targets.

The risk of additional attacks against Western targets in Nigeria remains high.

These incidents show a willingness on the part of some terrorist groups to attack Western targets.

The authorities say extremist groups have plotted attacks on Western targets.

Libya has also retreated from attacks against Western targets, the officials said.

Attacks on Western targets have killed 39 people and injured hundreds over the last year.

The group is recruiting new members, training them and planning new attacks on Western targets, the officials said.

"Its ability to devise increasingly sophisticated plots to attack Western targets is now a serious concern."

There have been three fatal attacks on Western targets in the last four months.

Israeli operatives were sent to carry out attacks on Western targets in Egypt.