A Royal Dutch Shell PLC joint venture said April 21 it may not be able to deliver some 169,000 barrels per day of crude in April and May because militants sabotaged a pipeline recently in southern Nigeria, where militancy and lawlessness has grown in recent years.

The unrest in Nigeria, the announcement by Shell and a missile attack on a Japanese oil tanker off the east coast of Yemen sent oil prices spiking to a record $117.40 a barrel April 21.

The Movement for the Emancipation of the Niger Delta, or MEND, took credit for the recent pipeline attack.