BBC News with John Jason

The security forces in Pakistan have been fighting a

lengthy

battle with militants who attacked a naval base in the city of Karachi overnight. Around a dozen well-armed attackers entered the base, setting off explosives. Eleven people are reported to have been killed, and a number have been taken hostage, including Chinese military staff. The Pakistani Taliban say they are responsible. Fighting is continuing in one part of the base, where the authorities say they've surrounded the militants. From Karachi, Shoaib Hasan reports.

Flames can be seen in the distance, and

intermittent

gunfire continues as troops battle the militants inside. Security officials told the BBC that several gunmen stormed the heavily-guarded Mehran naval air base late in the evening in central Karachi. Their first targets were aircraft parked on the

tarmac

and equipment in nearby hangers. Eyewitnesses say the militants used rocket-propelled grenades to damage and destroy several warplanes. These include the Pakistan army's premier anti-submarine attack jet - the US-made P-3C Orion. At least two of these multi-million-dollar aircraft were

set ablaze

.

Gulf Arab states have

suspend

ed their efforts to negotiate a power transfer deal in Yemen after President Ali Abdullah Saleh refused to sign it. The deal was meant to

pave the way for

Mr Saleh's resignation after months of pro-democracy protests in Yemen. State television reported that President Saleh would only sign it in the presence of opposition leaders. At one point, Western and Arab diplomats trying to