The centre issued an announcement on TV saying 31 earthquakes measured at 4.0 to 5.3 on Richter scale happened on the seedbed about 400 to 600 kilometres west of Ranong's coast on Thursday, Fridayd Saturday.

It said the number of the quakes was irregular and the epicenter was at a fault where undersea mountains were located and sometimes lava had seeped out from the fault.

The centre said the quakes might have been caused by force of the lava which were pushing out through the fault or the moving of the fault.

The centre said the quakes could lead to a formation of a new undersea volcano, which could cause tsunamis if the volcano exploded.

The centre added that the quakes also indicated that the Bahrain Volcano, which was about 110 kms away from the fault or 67kms from Thailand might explode in the future and affect Thailand.

The centre asked Thais to monitor announcements from the centre closely and ask fishermen to watch out for possible signs of undersea volcano explosion, such as the change of sea colours and strange behaviours of sea animals and smelling of phosphorous and seeing bubbles coming up from the sea.

Following the announcement, Phuket authorities have asked people to closely monitor announcements of DNWC and alerted the authorities if they found irregular incidents at the sea.

Phuket Governer Udomsak Assawarangkura said the number of earthquakes from March 9-11 were irregular. And the quakes could cause volcano underwater explosion that could possibly lead to tsunami.

He asked fishermen to monitor unusual incidents at sea such as change of sea colour or strange behaviour of sea animals. If found, they were asked to alert the nearest authorities.

As of now, the authorities have not yet issued any warning or ordered evacuation. But they are closely monitor the announcement from the DNWC.

Agence France-Presse, meanwhile, reports from Wellington that a string of moderate earthquakes shook New Zealand Saturday but there were no reports of damage or injury.

It says the largest quake measured 4.6 on the Richter scale and struck 40 kilometres west of remote Te Anau on the west coast of the South Island, the New Zealand Geological and Nuclear Sciences Department said.

A series of four quakes ranging from 3.8 to 4.5 rocked Wanganui on the west coast of the North Island over an eight hour period.

Menawhile a 5.2-magnitude earthquake jolted northern Pakistan on Friday, killing one person and injuring 22.

The quake was an aftershock of the massive October 8 South Asian temblor that killed more than 73,000 people in Pakistan, seismological department chief Qamaruz Zaman told AFP.

The tremor was felt at 12:50 pm (0750 GMT) in Jhelum and Lahore in Punjab province and in the city of Mirpur in Pakistan-administered Kashmir, Zaman said, adding the epicentre was located between Jhelum and Mirpur.