(Adds details on attack, Algeria, BP statement)
OSLO/ALGIERS March 18 (Reuters) - Militants attacked anAlgerian gas plant operated by Norway's Statoil and BP with rocket-propelled grenades on Friday, but there wereno casualties or damage, the companies and sources said.
Algeria's energy infrastructure is heavily protected by thearmy especially since the 2013 Islamist militant attack on theIn Amenas gas plant, also operated by BP and Statoil, duringwhich 40 oil workers were killed.
Stateoil said in a statement that the gas facility was hitby explosive munitions from a distance.
"In the early morning, three or four rocket propelledgrenades hit a central processing facility, there were nocasualties or damage reported," an industry source.
The Algerian army were controlling the area and pursuing theattackers. BP said in a statement that the facility had beenclosed down as a safety precaution.
Militant attacks in Algeria, one of Europe's main gassuppliers, have become rarer since the North African countryemerged from a 1990s war with Islamist fighters that killedaround 200,000 people.
But Al Qaeda in the Islamic Maghreb, and its affiliates, andfighters allied with Islamic State, are active in remote pocketsof the country, mainly in the desert south and the mountainseast of the capital Algiers.
Algeria and other North African countries are alsoincreasingly worried about the rapid expansion of Islamic Stateover their border in Libya, where the militant group has takenover the city of Sirte and attacked oilfields and ports. (Reporting by Terje Solsvik in Olso, and Patrick Markey inAlgiers, Editing by Angus MacSwan)